阅读说明：本技术 Ggpp结合并变构激活人源fbp1在制备抗肝细胞癌药物中的应用 (Application of GGPP (gas-gas phase plasma) combination and allosteric activation of humanized FBP1 in preparation of anti-hepatocellular carcinoma drugs ) 是由 方雷 章竞子 李朝军 赵越 于 2021-08-27 设计创作，主要内容包括：本发明公开了GGPP结合并变构激活人源FBP1在制备抗肝细胞癌药物中的应用。所述的人源FBP1蛋白的氨基酸序列如SEQID No.1所示。本发明建立了正常肝脏中GGPP的直接结合蛋白作用网络,并筛选和验证了多个参与肝脏糖脂代谢调控的GGPP结合蛋白。所述的GGPP特异地与FBP1结合并上调FBP1的酶活促进糖异生,可且抑制肝实质细胞和肝癌细胞的迁移。所述的GGPP通过敏化其靶点蛋白FBP1偶联糖脂代谢平衡,进而调节肝细胞癌发生、发展的分子机制,可应用于肝细胞癌的治疗。GGPP通过与其靶点蛋白FBP1特异性直接结合调控肝脏糖脂代谢平衡,并为HCC的治疗提供新的潜在靶点、药物和治疗方法。(The invention discloses application of GGPP (GGPP) combination and allosteric activation of humanized FBP1 in preparation of anti-hepatocellular carcinoma drugs. The amino acid sequence of the human FBP1 protein is shown as SEQID No. 1. The invention establishes a direct binding protein action network of GGPP in normal liver, and screens and verifies a plurality of GGPP binding proteins participating in regulation and control of hepatic glycolipid metabolism. The GGPP is specifically combined with FBP1 and up-regulates the enzyme activity of FBP1 to promote gluconeogenesis, and can inhibit the migration of liver parenchymal cells and liver cancer cells. The GGPP is coupled with glycolipid metabolic balance through sensitizing a target protein FBP1 of the GGPP, so that a molecular mechanism for generation and development of hepatocellular carcinoma is regulated, and the GGPP can be applied to treatment of the hepatocellular carcinoma. GGPP regulates the metabolic balance of hepatic glycolipids by specifically and directly combining with a target protein FBP1, and provides a new potential target, a medicine and a treatment method for treating HCC.)

1. The application of geranylgeranyl pyrophosphate GGPP (GGPP) in combination and allosteric activation of human fructose-1, 6-diphosphatase 1FBP1 in preparation of anti-hepatocellular carcinoma drugs is characterized in that: the chemical formula of GGPP is shown as the formula (I):

the amino acid sequence of the human FBP1 protein is shown in SEQ ID No. 1.

2. Use according to claim 1, characterized in that: the geranylgeranyl pyrophosphate GGPP is specifically combined with FBP1 and up-regulates the enzyme activity of FBP1 to promote gluconeogenesis and inhibit the migration of liver parenchyma cells and liver cancer cells.

3. Use according to claim 2, characterized in that: the geranylgeranyl pyrophosphate GGPP is coupled with glycolipid metabolic balance by sensitizing a target protein FBP1 of the geranylgeranyl pyrophosphate GGPP so as to regulate a molecular mechanism for the occurrence and development of hepatocellular carcinoma, and can be applied to the treatment of hepatocellular carcinoma.

4. Use according to claim 3, characterized in that: synthesizing a GGPP probe with a Biotin label, enriching GGPP binding protein in primary liver parenchymal cells of a mouse by using a Biotin-streptavidin affinity purification system, and performing mass spectrometry to screen out a plurality of GGPP potential target proteins related to glycolipid metabolism, fructose-1, 6-diphosphatase 1 in a gluconeogenesis pathway, liver pyruvate kinase in a glycolysis pathway and carnitine palmitoyltransferase 1 involved in lipid oxidation.

5. Use according to claim 1 or 4, characterized in that: the GGPP is specifically combined with FBP1 and up-regulates the enzyme activity of FBP1 to promote gluconeogenesis and reverse the Warburg effect of tumors so as to inhibit the occurrence and development of various tumors.

6. Use according to claim 1 or 4, characterized in that: the anti-tumor drug is an anti-hepatocellular carcinoma drug.

Technical Field

The invention relates to the technical field of biology, in particular to application of geranylgeranyl pyrophosphate GGPP (GGPP) combination and allosteric activation of humanized FBP1 in preparation of an anti-hepatocellular carcinoma drug.

Background

Regulation of glycolipid metabolic homeostasis is the basis for maintaining the body's vital activities. In China, due to changes of life styles and dietary structures in recent decades, glycolipid metabolic modes of partial crowds are changed, and the incidence rate of metabolic syndromes such as obesity and diabetes is remarkably increased. Liver plays the first place as a central organ of metabolism, and chronic Liver diseases such as Non-alcoholic fatty Liver disease (NAFLD) and hepatic fibrosis (Liver fibrosis) are caused by long-term disturbance of glycolipid metabolism. Recent research results show that in addition to viral hepatitis and alcoholic liver diseases, metabolic syndrome, NAFLD and other chronic liver diseases are also important causes of primary liver cancer. Meanwhile, by controlling glycolipid metabolism of cancer cells, prevention and treatment of cancer by specifically blocking energy sources of cancer cells using various strategies are also receiving increasing attention. Therefore, glycolipid metabolic homeostasis plays an important role in the development, prevention, early diagnosis and treatment of primary liver cancer.

Hepatocellular carcinoma (HCC), the major type of primary liver cancer, is one of the most common in vivo malignancies worldwide and one of the most common causes of tumor-related death. In addition to surgical treatment, Sorafenib (Sorafenib), a multi-kinase inhibitor, is the only drug approved by many countries for systemic treatment of advanced HCC in patients with advanced liver cancer, but is expensive, has special adverse reactions, and leaves doubt on the effectiveness of different patients. In addition, in the development of new drugs, clinical tests of other molecular targeting preparations such as Sunitinib (Sunitinib), Brivanib (Brivanib) and linivanib (linifib) for treating liver cancer all obtain a series of negative results. The new application of old drugs is a new trend of drug research and development due to the fact that research and development time, cost and clinical application period can be greatly shortened in the process of drug research and development with high investment and high risk. As a clinical most common lipid-lowering prescription drug, the population of Statins (Statins) is wide, and the drug is mainly applied to the treatment and prevention of hyperlipidemia and various cardiovascular diseases accompanied by metabolic syndrome. Recent large clinical statistics show that Statins can reduce the risk of death in patients with various cancers such as HCC, suggesting the possibility of HCC as a new indication for Statins. However, there is still uncertainty about the role of statins in HCC prevention and treatment. This may be related to the fact that statins inhibit the hydroxymethyl glutaryl-coenzyme a reductase (3-hydroxy-3-methylglutaryl-CoA reductase, HMGCR) located upstream of the mevalonate pathway, leading to the synthesis of a number of metabolic small molecules downstream thereof with important biological functions, such as Farnesyl pyrophosphate (FPP), Squalene (Squalene), Cholesterol (Cholesterol), Geranylgeranyl pyrophosphate (GGPP) and Ubiquinone (Ubiquinone), which are hindered (as shown in fig. 1).

The body's response to these metabolic small molecule deletions is extremely complex, which may be one of the important reasons why statins have significant differences in their therapeutic effects on different cancer types and even on different individual patients. The function of the small molecules in the metabolic pathway of mevalonate in the occurrence and development of HCC is clarified, and the application of statins in HCC treatment and the further development of related treatment schemes are of great significance. FIG. 1 is a diagram of the mevalonate pathway.

Among them, Geranylgeranyl pyrophosphate (GGPP) is one of important metabolic small molecules downstream of mevalonate pathway, and is another important product of Farnesyl pyrophosphate (FPP) besides cholesterol (as shown in fig. 1). FPP and GGPP have been reported to have main functions of participating in important protein lipid acylation modification, namely prenylation modification, as substrates, and the positions and activities of certain specific proteins on a membrane system are changed by respectively changing the hydrophobicity of the specific proteins so as to regulate and control a downstream signal path, thereby playing specific functions.

Geranylgeranyl pyrophosphate synthase 1(Geranylgeranyl pyrophosphate synthase 1, GGPPS1) is a synthase responsible for catalyzing the conversion of FPP to GGPP in vivo. The laboratory utilizes Ggpps1 specific knockout mice in different organ tissues to research the influence of the relative change of FPP and GGPP levels on the body functions. The explanation of the Ggpps1 knockout mouse phenotype focuses on the change of the prenylation modification mode of a protein after the balance of FPP/GGPP is disrupted, namely geranylation modification is deleted, and the downstream signal path is changed due to the excessive farnesylation activation of a specific protein, so that a series of phenotypes, such as adult mouse cardiac hypertrophy, male mouse reproductive disorder, female mouse oocyte developmental disorder and the like, appear. Analysis of skeletal muscle specificity Ggpps1 knockout heterozygote mice shows that the GGPPS1 deletion triggers high fat-induced systemic insulin resistance, and the GGPPS1 is proved to be involved in lipid metabolism regulation. Research on liver-specific Ggpps1 knockout mice shows that the Ggpps1 knockout reduces the level of GGPP in the liver of the mice and also reduces fat accumulation caused by high-fat food in the liver, and the GGPP is suggested to have an important regulating effect on the glycolipid metabolic balance of the liver. More importantly, liver-specific Ggpps1 knockout mice are more prone to develop primary liver cancer when subjected to DEN chemical mutagenesis; the clinical detection of liver cancer samples of HCC patients shows that the expression level of the synthetase GGPPS1 of GGPP is positively correlated with the malignancy degree of HCC, and the HCC patients with high expression of GGPPS1 have better prognosis, which indicates that GGPPS1 and GGPP can be compensated and up-regulated in the HCC exacerbation process to protect the liver. Meanwhile, Metadrug software analysis of Keruiwei-an also showed that GGPP had significant antitumor activity. These results suggest that GGPP plays an important role in regulation of hepatic glycolipid metabolism and development of liver cancer, but the direct target protein regulated by GGPP and the corresponding action mechanism are not known at present.

FBP1 is a key rate-limiting enzyme in gluconeogenesis and has also been shown to be an important oncostatin. There are many studies reporting that deletion, mutation and reduced expression of FBP1 may cause the occurrence and development of various cancers such as hepatocellular carcinoma, renal clear cell carcinoma, non-small cell lung cancer, breast cancer, etc. In HCC, the deletion or reduction of FBP1 can influence Warburg effect to cause glycolipid metabolic disorder and abnormal accumulation of lipid, provide a large amount of substance and energy for cancer cells, and accelerate the occurrence and development of HCC. Statistical data also indicate that patients with high expression levels of FBP1 in HCC have a significantly better prognosis, making FBP1 a potential prognostic marker for HCC.

At present, the application of geranylgeranyl pyrophosphate GGPP (GGPP) in combination and allosteric activation of human FBP1 in preparation of anti-hepatocellular carcinoma drugs is lacked.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides an application of geranylgeranyl pyrophosphate GGPP (GGPP) combination and allosterically activated human FBP1 in preparation of an anti-hepatocellular carcinoma drug.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows: the invention discloses an application of geranylgeranyl pyrophosphate GGPP (GGPl) in combination and allosteric activation of humanized FBP1 in preparation of anti-hepatocellular carcinoma drugs, wherein the chemical formula of geranylgeranyl pyrophosphate GGPP is shown as a formula (I):

the amino acid sequence of the human FBP1 protein is shown as SEQID No. 1.

Further, the geranylgeranyl pyrophosphate GGPP specifically binds to FBP1 and up-regulates the enzymatic activity of FBP1 to promote gluconeogenesis and inhibit the migration of parenchymal liver cells and liver cancer cells.

Furthermore, the geranylgeranyl pyrophosphate GGPP is coupled with glycolipid metabolic balance by sensitizing a target protein FBP1 of the geranylgeranyl pyrophosphate GGPP, so as to regulate the molecular mechanism of the occurrence and development of hepatocellular carcinoma and act on the hepatocellular carcinoma.

Furthermore, a GGPP probe with a Biotin label is synthesized, a Biotin-streptavidin affinity purification system is utilized to enrich GGPP binding protein in primary liver parenchymal cells of mice, mass spectrum detection is carried out, and a plurality of GGPP potential target proteins related to glycolipid metabolism, fructose-1, 6-diphosphatase 1 in a gluconeogenesis pathway, liver pyruvate kinase in a glycolysis pathway and carnitine palmitoyltransferase 1 involved in lipid oxidation are screened out.

Further, the GGPP specifically binds to FBP1 and up-regulates the enzyme activity of FBP1 to promote gluconeogenesis and reverse the Warburg effect of tumors so as to inhibit the occurrence and development of various tumors.

Furthermore, the anti-tumor drug is an anti-hepatocellular carcinoma drug.

Has the advantages that: the invention adopts a high-flux chemical proteomics method to establish a direct binding protein action network of geranylgeranyl pyrophosphate GGPP in normal liver for the first time, and screens and verifies a plurality of GGPP binding proteins participating in regulation and control of liver glycolipid metabolism. From a plurality of aspects such as molecular level, cell level, animal model and clinical case, the GGPP regulates and controls the metabolic balance of the hepatic glycolipid by the specific direct combination with the target protein FBP1, thereby regulating the molecular mechanism of the generation and development of HCC and providing a new potential target, a drug and a treatment method for the treatment of HCC.

Compared with the prior art, the invention has the following advantages: according to further research on interaction of geranylgeranyl pyrophosphate GGPP and FBP1, the GGPP can be specifically combined with FBP1 and can be used for up-regulating enzyme activity of FBP1 to promote gluconeogenesis and inhibiting migration of parenchymal hepatic cells and liver cancer cells; by means of molecular docking, FBP1 mutant and cryo-electron microscopy experiments, the invention confirms the binding mode of GGPP and FBP1, key sites and the mechanism of allosterically activating FBP 1. The molecular mechanism of the GGPP for regulating the occurrence and development of the hepatocellular carcinoma by sensitizing the target protein FBP1 coupled glycolipid metabolic balance of the GGPP is deeply clarified, and potential drugs and targets are provided for the treatment of the hepatocellular carcinoma.

Drawings

FIG. 1 is a diagram of the mevalonate pathway.

FIG. 2 is a Biotin-labeled Biotin-GGPP (BGPP) molecular diagram of the present invention.

FIG. 3 is a technical route diagram of the metabolic small molecule GGPP target protein screening method of the invention.

FIG. 4 is an affinity purification diagram of the metabolic small molecule GGPP target protein of the invention.

FIG. 5 is a bioinformatic analysis of the GGPP potential direct binding protein of the present invention. Gene Ontology analysis of GGPP binding protein, including biological processes, molecular functions and cellular component analysis; KEGG pathway analysis of ggpp binding protein; functional classification of ggpp binding proteins; analysis of protein-protein interaction networks of key enzymes regulating carbohydrate metabolism and lipid metabolism in ggpp-binding proteins.

FIG. 6 is a table of FPP/GGPP ratios of liver-specific Ggpps1 knockout mice of the invention. A. The ratio of FPP/GGPP and FOH/GGOH of primary liver parenchymal cells of a liver-specific Ggpps1 knockout mouse is changed; B. wild type and liver-specific Ggpps1 knockout liver morphology under normal diet and high fat induction; C. HE staining of liver sections from wild-type and liver-specific Ggpps1 knockouts, vacuoles or lipid droplets shown in the WT HFD group; D. liver sections from wild-type and liver-specific Ggpps1 knockouts were oil red stained, and red dots indicated lipid droplets in the liver.

FIG. 7 shows peptide fragments and secondary spectra of GGPP-binding protein FBP1 identified by affinity purification mass spectrometry of the invention. A. The peptide condition of GGPP binding protein FBP1 identified by two times of affinity purification mass spectra; b. fbp1 peptide DFDPAINEYLQR2+ (m/z 740.85) secondary spectrum.

FIG. 8 shows Western blot and MST verification of a plurality of GGPP-binding proteins of the present invention. Western blot verification of GGPP binding proteins such as FBP1, ACARDL, ACSL1 and the like; validation of binding of fbp1, ACADL and ACSL1 to GGPP; validation of fbp1, ACADL and ACSL1 in combination with BGPP.

FIG. 9 shows the competitive binding experiment of GGPP-binding protein FBP1 of the present invention and the verification of SPR and BLI. Competitive binding experiments for the ggpp binding protein FBP 1; SPR verification of ggpp and FBP1 binding; validation of BLI binding of ggpp and FBP 1.

FIG. 10 is a graph showing that the GGPP of the invention binds to FBP1 and then significantly up-regulates the enzyme activity of FBP 1. Ggpp binding to FBP1 did not affect FBP1 homotetramer formation; ggpp and FBP1 binding significantly up-regulated FBP1 enzyme activity, whereas FPP had no activating effect.

FIG. 11 is a graph showing structural changes of FBP1 tetramer after GGPP binds to FBP1 by negative staining electron microscopy of the present invention. Negative staining electron microscope integral results of FBP1 tetramer after addition of FBP1 and GGPP; collecting FBP1 and GGPP-FBP1 particles with different conformations by using a negative dye electron microscope after C-D magnification; E-F3D reconstruction of the particle conformations of negative stain electron microscopy FBP1 and GGPP-FBP 1; g-j.3d reconstitution revealed conformational and turn changes in FBP1 tetramer upon GGPP binding.

FIG. 12 is a graph of the central cavity of an FBP1 tetramer in which GGPP binding is revealed by X-ray crystallography according to the present invention.

FIG. 13 is a diagram showing that the mutation at FBP1-R50 site of the present invention inhibits the activity of FBP1 in inhibiting hepatoma cells in response to GGPP stimulation. R50 reduces the ability of FBP1 to inhibit the viability and proliferation of hepatoma cells Huh7 in response to GGPP stimulation; the mutation of C-D.R50 reduces the ability of FBP1 to inhibit the viability and proliferation of hepatoma cells HepG2 in response to GGPP stimulation.

FIG. 14 is a graph showing that the GGPP-binding site mutation of human FBP1 protein of the invention inhibits the activity of FBP1 enzyme in response to GGPP stimulation. Ggpp binding site mutations do not affect FBP1 homotetramer formation; GGPP binding site mutations inhibit FBP1 enzymatic activity in response to GGPP stimulation.

FIG. 15 is a graph showing that GGPP precursor GGOH of the present invention can reverse the occurrence and development of hepatocellular carcinoma in mice. A. High fat diet and chemical mutagenesis to make a time line of mouse primary hepatocellular carcinoma model; B. normal control group, high fat diet and chemical mutagenesis mice primary hepatocellular carcinoma group and reversal after GGOH anaplerosis; the degree of malignancy of hepatocellular carcinoma in three groups of mice in C-E.B was compared and statistical analysis of the number and volume of tumors was performed.

FIG. 16 is a graph showing that GGPP treatment of the present invention significantly inhibited the viability and proliferation of hepatoma cells. GGPP treatment obviously inhibits the activity and proliferation of liver cancer cells Huh 7; GGPP treatment obviously inhibits the activity and proliferation of liver cancer cells HepG 2.

Detailed Description

In order to facilitate an understanding of the invention, the invention will now be described more fully hereinafter with reference to the accompanying drawings, in which several embodiments of the invention are shown, but which may be embodied in different forms and not limited to the embodiments described herein, but which are provided so as to provide a more thorough and complete disclosure of the invention.

The invention discloses an application of geranylgeranyl pyrophosphate GGPP (GGPl) in combination and allosteric activation of humanized FBP1 in preparation of anti-hepatocellular carcinoma drugs, wherein the chemical formula of geranylgeranyl pyrophosphate GGPP is shown as a formula (I):

the amino acid sequence of the human FBP1 protein is shown as SEQID No. 1.

The geranylgeranyl pyrophosphate GGPP is specifically combined with FBP1 and up-regulates the enzyme activity of FBP1 to promote gluconeogenesis and inhibit the migration of liver parenchyma cells and liver cancer cells.

The geranylgeranyl pyrophosphate GGPP is coupled with glycolipid metabolic balance by sensitizing a target protein FBP1 of the geranylgeranyl pyrophosphate GGPP, so as to regulate a molecular mechanism for the occurrence and development of hepatocellular carcinoma and act on the hepatocellular carcinoma.

Synthesizing a GGPP probe with a Biotin label, enriching GGPP binding protein in primary liver parenchymal cells of a mouse by using a Biotin-streptavidin affinity purification system, and performing mass spectrometry to screen out a plurality of GGPP potential target proteins related to glycolipid metabolism, fructose-1, 6-diphosphatase 1 in a gluconeogenesis pathway, liver pyruvate kinase in a glycolysis pathway and carnitine palmitoyltransferase 1 involved in lipid oxidation.

The GGPP is specifically combined with FBP1 and up-regulates the enzyme activity of FBP1 to promote gluconeogenesis and reverse the Warburg effect of tumors so as to inhibit the occurrence and development of various tumors.

The anti-tumor drug is an anti-hepatocellular carcinoma drug.

Example 1

A Biotin-labeled GGPP probe is used for enriching GGPP binding protein in primary Liver parenchyma cells of mice by using a Biotin-streptavidin affinity purification system and performing mass spectrometry, so that a plurality of GGPP potential target proteins related to glycolipid metabolism are screened, such as Fructose-1, 6-diphosphatase 1(Fructose-1, 6-biphosphatase, FBP1) in a gluconeogenesis pathway, Liver Pyruvate Kinase (LPK) in a glycolysis pathway, Carnitine palmitoyltransferase 1 (CPT 1) involved in lipid oxidation and the like. Among them, FBP1 has attracted attention due to its significance in binding to GGPP (as shown in fig. 5-8), its important role in regulation of glycolipid metabolism, and its association with various cancers.

1. Establishing a technical route for enriching and identifying the metabolic small molecule GGPP direct binding protein

1.1 design and Synthesis of Biotin-GGPP Probe

In order to enrich the liver for proteins that bind directly to GGPP, the present invention synthesizes biotin-tagged GGPP probes (BGPP, FIG. 2). In the BGPP molecule, biotin is added at the C3 position of the long-chain carbon skeleton of GGPP molecule with a biotin label, so as to ensure the flexibility of the front hydrophobic long chain and the rear pyrophosphate of GGPP and expose the interaction with the binding protein of GGPP. FIG. 2 is a Biotin-labeled Biotin-GGPP (BGPP) molecular diagram of the present invention.

The chemical formula of the GGPP (Chinese name: geranylgeranyl pyrophosphate) is shown as a formula (I):

1.2 general metabolic small molecule or drug small molecule target protein screening technical route

The invention establishes a general metabolic small molecule or drug small molecule target protein screening technical route (figure 3). To identify target proteins in the liver that bind directly to and are regulated by GGPP, we synthesized biotin-tagged GGPP molecules and treated isolated, cultured primary hepatocytes of 8-week-old C57BL/6J male mice, respectively, with biotin and GGPP alone as controls. After total protein is extracted from the lysed cells, GGPP binding protein is purified through streptavidin magnetic bead affinity, mass spectrometry is carried out by using 2D LC-MS/MS, and then a possible GGPP interaction protein group in primary parenchymal hepatocytes of adult mice is obtained by combining unlabeled proteomics quantification and biological information analysis based on spectrogram number calculation. Through the technical route, the invention can screen the direct binding protein of important metabolic small molecules or drug small molecules in human bodies or cells, and provides targets and theoretical basis for explaining the biological activity and the acting molecular mechanism of the small molecules. FIG. 3 is a technical route for screening a metabolic small molecule GGPP target protein; FIG. 4 is an affinity purification diagram of the metabolic small molecule GGPP target protein of the invention.

In the invention, primary hepatic parenchymal cells of an 8-week-old C57BL/6J male mouse are separated and are divided into three parts to be cultured respectively. When experimental grouping was performed with addition of small molecule drugs, two negative controls were set: separately cultured primary hepatocytes of mice were treated with a (Biotin & GGPP) addition group and a (BGPP & 8-fold GGPP) competition group, respectively, and a BGPP addition group, respectively. After 4 hours of drug addition, three groups of mouse primary hepatocytes were lysed to extract total protein (Input) and affinity purified by addition of streptavidin magnetic beads to obtain potential GGPP Acting Protein (AP) in adult mouse primary hepatocytes. After silver staining is carried out on the binding protein obtained by affinity purification of the Biotin-GGPP, a plurality of obvious difference bands are found in the Biotin-GGPP group compared with the Biotin group (figure 4), which indicates that the GGPP may indeed have specific binding protein. Therefore, the invention carries out further LC-MS/MS mass spectrometry analysis on the proteins. FIG. 5 is a bioinformatic analysis of GGPP potential direct binding proteins of the present invention; gene Ontology analysis of GGPP binding protein, including biological processes, molecular functions and cellular component analysis; KEGG pathway analysis of ggpp binding protein; functional classification of ggpp binding proteins; analysis of protein-protein interaction networks of key enzymes regulating carbohydrate metabolism and lipid metabolism in ggpp-binding proteins.

After database search is carried out on the mass spectrum raw data, 259 and 479 proteins are respectively detected by a Biotin control group and a Biotin-GGPP treatment group. And integrating the data of the two groups for performing Label Free relative quantitative comparison, and obtaining 211 potential GGPP binding proteins by taking the standards that the relative abundance is up-regulated by more than 1.5 times in a Biotin-GGPP group compared with a Biotin control group and the number of detected peptide segments is more than 1. Bioinformatic analyses of these 211 proteins, including Gene Ontology analysis (fig. 5A-C), KEGG Pathway analysis (fig. 5D), protein functional classification analysis (fig. 5E) and protein-protein interaction network analysis (fig. 5F), showed the results: these proteins are involved in a large number of various metabolic processes, notably in fatty acid metabolism and the glycolysis/gluconeogenesis pathway. These glycolipid metabolism-associated proteins such as CPT1 alpha and FBP1 can be candidate proteins for subsequent study on the mechanism of GGPP in regulating liver metabolic diseases and hepatocellular carcinoma (Table 1). Key enzymes regulating hepatic glycolipid metabolism in the GGPP direct binding proteins of the invention are shown in table 1:

test example 1

Construction and phenotypic analysis of liver-specific Ggpps1 knockout mice

In order to research the influence of GGPP deletion on liver lipid metabolism, the invention successfully constructs Ggpps1^-/-Mx1-Cre liver-specific induced knockout mice and associated phenotypic analysis was performed. In liver-specific Ggpps1 knockout mouse liver primary cells, metabonomic mass spectrometric detection shows that the ratios of FPP/GGPP and FOH/GGOH are remarkably increased (FIG. 6A), and the reduction of GGPP content and the increase of FPP content remarkably inhibit the accumulation of Triglyceride (TG) in liver-specific Ggpps1 knockout mice, so that knockout mice are not sensitive to high fat diet induction and do not have obvious fatty liver phenotype (FIGS. 6B-D). FIG. 6 shows FPP/GGPP ratios and phenotypes of liver-specific Ggpps1 knockout mice of the present invention; A. the ratio of FPP/GGPP and FOH/GGOH of primary liver parenchymal cells of a liver-specific Ggpps1 knockout mouse is changed; B. wild type and liver-specific Ggpps1 knockout liver morphology under normal diet and high fat induction; C. HE staining of liver sections from wild-type and liver-specific Ggpps1 knockouts, vacuoles or lipid droplets shown in the WT HFD group; D. liver sections from wild-type and liver-specific Ggpps1 knockouts were oil red stained, and red dots indicated lipid droplets in the liver.

Test example 2

GGPP regulates and controls hepatic glycolipid metabolism to participate in the occurrence and development of hepatocellular carcinoma by combining with FBP1

FBP1 is a key rate-limiting enzyme in gluconeogenesis and has also been shown to be an important oncostatin. There are many studies reporting that deletion, mutation and reduced expression of FBP1 may cause the occurrence and development of various cancers such as hepatocellular carcinoma, renal clear cell carcinoma, non-small cell lung cancer, breast cancer, etc. In stem cell cancer HCC, the deletion or reduction of FBP1 can influence Warburg effect to cause glycolipid metabolic disorder and abnormal accumulation of lipid, provide a large amount of substances and energy for cancer cells, and accelerate the occurrence and development of HCC. Statistical data also indicate that patients with high expression levels of FBP1 in HCC have a significantly better prognosis, making FBP1 a potential prognostic marker for HCC.

Clinically, the expression level of the synthetase GGPPS1 of GGPP is positively correlated with the malignancy degree of HCC in HCC patient samples, and the HCC patient with high expression of GGPPS1 has better prognosis, which suggests that GGPPS1 and GGPP may be up-regulated in the HCC exacerbation process by compensation to protect the liver. It is speculated that GGPP is involved in the generation and development of HCC by binding FBP1 and up-regulating its activity to influence glycolipid metabolic balance. Therefore, the invention clarifies the molecular mechanism that GGPP regulates glycolipid metabolism balance through the specific direct combination with the target protein FBP1 of GGPP, thereby regulating the generation and development of HCC, and provides a new potential target, a medicine and a treatment method for the treatment of HCC from a plurality of aspects such as molecular level, cell level, animal model and clinical case.

Secondary spectrum of 1 GGPP binding protein FBP1 peptide fragment

In two affinity purification repeated experiments with BGPP as a probe, the human FBP1 protein is identified in the invention, the number of peptide fragments identified by protein mass spectrum is 7 and 5 respectively, and the overall coverage rate of the human FBP1 protein is 28.7% and 26% respectively (FIG. 7A). FBP1 peptide DFDPAINEYLQR²⁺The B-series and y-series ion peaks of the (m/z-740.85) secondary spectrum perfectly covered the entire peptide fragment (fig. 7B), suggesting without doubt that the present invention indeed identified FBP1 in BGPP binding proteins. FIG. 7 shows peptide fragments and secondary spectra of GGPP-binding protein FBP1 identified by affinity purification mass spectrometry according to the present invention; A. the peptide condition of GGPP binding protein FBP1 identified by two times of affinity purification mass spectra; FBP1 peptide DFDPAINEYLQR²⁺(m/z-740.85) secondary spectrum.

Western blot and MST verification of 2 GGPP binding protein FBP1

Through Western blot, the invention verifies that FBP1, ACADL and ACSL1 in BGPP binding protein are as follows: the AP samples from the BGPP group contained significantly enriched FBP1, ACADL and ACSL1 proteins compared to the negative control group of Biotin & GPPP (fig. 8A). Meanwhile, in order to further verify the direct binding of glycolipid metabolism-related proteins such as FBP1, ACADAL and ACSL1 and GGPP, the fusion protein with an EGFP label is expressed and purified by using an escherichia coli prokaryotic expression system, and then micro-calorimetric electrophoresis (MST) analysis is carried out, so that the FBP1, ACADAL and ACSL1 proteins can be specifically and directly bound with GGPP, and the dissociation constant KD value of the combination of FBP1 and GGPP is 250nM (FIGS. 8B-C). FIG. 8 is a Western blot and MST validation graph of a plurality of GGPP-binding proteins of the invention; western blot verification of GGPP binding proteins such as FBP1, ACARDL, ACSL1 and the like; validation of binding of fbp1, ACADL and ACSL1 to GGPP; validation of fbp1, ACADL and ACSL1 in combination with BGPP.

Competitive binding experiments with 3 GGPP binding to FBP1, SPR and BLI

FBP1 as a candidate molecule for subsequent biological function studies was further subjected to binding verification of GGPP in various ways. The GGPP competitive binding experiments show that the binding of BGPP to human FBP1 protein decreases in a dose-dependent manner when high doses of free GGPP molecules are present. When the concentration of free GGPP reached 40 μ M (8-fold that of the BGPP probe), binding of BGPP and FBP1 was almost completely disrupted, demonstrating that BGPP specifically binds directly to human FBP1 protein (fig. 9A). Experiments such as Surface Plasmon Resonance (SPR) (fig. 9B) and molecular interaction (BLI) (fig. 9C) also showed that FBP1 recombinant protein purified from e.coli can specifically bind to GGPP in vitro. Dissociation constant K of FBP1 and GGPP binding detected by SPR_DThe value was 262nM (FIG. 9B). FIG. 9 shows the competitive binding assay of the GGPP-binding protein FBP1 of the invention and the verification of SPR and BLI; competitive binding experiments for the ggpp binding protein FBP 1; SPR verification of ggpp and FBP1 binding; validation of BLI binding of ggpp and FBP 1.

4 GGPP combines to up-regulate the enzyme activity of FBP 1; FIG. 10 significant upregulation of FBP1 enzymatic activity following binding of GGPP to FBP 1; ggpp binding to FBP1 did not affect FBP1 homotetramer formation; ggpp and FBP1 binding significantly up-regulated FBP1 enzyme activity, whereas FPP had no activating effect.

FBP1 is a key rate-limiting enzyme in gluconeogenesis. Therefore, it is important to research whether the GGPP combined with FBP1 influences the enzyme activity. To elucidate the biological function of direct binding of GGPP to FBP1, the present invention further examined the effect of GGPP on FBP1 activity. In vitro experiments demonstrated that GGPP did not affect FBP1 homotetramer formation (fig. 10A), but could significantly up-regulate FBP1 activity in a dose-dependent manner (fig. 10B), whereas FPP, which is structurally similar to GGPP, did not, indicating that GGPP specifically binds FBP1 and regulates its activity. The effectiveness of the detection system is proved by the fact that the activity of FBP1 is reduced in a dose-dependent manner by using AMP as an FBP1 activity inhibitor which is reported in the literature.

Characterization of the binding pattern of 5 GGPP and FBP 1; FIG. 11 is a negative stain electron micrograph showing the structural change of FBP1 tetramer after GGPP binds to FBP 1; negative staining electron microscope integral results of FBP1 tetramer after addition of FBP1 and GGPP; collecting FBP1 and GGPP-FBP1 particles with different conformations by using a negative dye electron microscope after C-D magnification; E-F3D reconstruction of the particle conformations of negative stain electron microscopy FBP1 and GGPP-FBP 1; g-j.3d reconstitution revealed conformational and turn changes in FBP1 tetramer upon GGPP binding.

In order to clarify the molecular mechanism of activating FBP1 activity by GGPP, the invention analyzes the conformational change of the FBP1 homologous protein tetramer after GGPP is added by a cryo-electron microscope. The results show that GGPP binding decreases the angle between the upper and lower FBP1 dimers in the FBP1 tetramer, resulting in a deflection of around 6 degrees (FIG. 11). After GGPP is added, the relative positions of two dimers in FBP1 tetramer can be better stabilized, and the relative angle between the two dimers is reduced. Further X-ray crystallography results indicated that GGPP molecules specifically bind to the central cavity of FBP1 tetramer, and FBP1 amino acid residues that directly interact with it include R50, S46, P189 and a190, etc. (fig. 12). This binding of GGPP acts like a "keeper" that blocks the rotation of the upper and lower dimers in FBP1 tetramer from being converted to the inactive R state, thereby leaving FBP1 tetramer largely in the active T state, up-regulating the activity of FBP 1. FIG. 12 is a graph of the central cavity of an FBP1 tetramer in which GGPP binding is revealed by X-ray crystallography according to the present invention.

According to the results of the above structural experiments, the present inventors constructed mutants of FBP1 and observed their ability to form FBP1 tetramer and changes in enzyme activity. The results showed that mutation of the GGPP binding site of the human FBP1 protein hardly affected FBP1 tetramer formation (fig. 14A), but significantly inhibited FBP1 enzymatic activity in response to GGPP stimulation (fig. 14B), confirming that these sites are critical for the binding of FBP1 and GGPP. FIG. 14 is a graph showing that mutations in the GGPP binding site of human FBP1 protein of the invention inhibit the activity of FBP1 enzyme in response to GGPP stimulation; ggpp binding site mutations do not affect FBP1 homotetramer formation; GGPP binding site mutations inhibit FBP1 enzymatic activity in response to GGPP stimulation.

6 GGPP and FBP1 combined to regulate the occurrence and development of hepatocellular carcinoma

In view of the important regulatory role of GGPP on the activity of FBP1 and the important function of FBP1 itself as a tumor suppressor, the invention researches the role of GGPP and FBP1 in the process of inhibiting the occurrence and development of mouse hepatocellular carcinoma. The results show that wild-type mice develop liver cancer when a mouse primary hepatocellular carcinoma model is made using high fat diet and chemical mutagenesis (fig. 15A-B); and the re-supplementation of GGOH to hepatoma-modeled mice can obviously inhibit the generation and development of liver cancer of the mice (FIGS. 15C-E). FIG. 15 is a graph showing that GGOH of the present invention can reverse the occurrence and development of hepatocellular carcinoma in mice; A. high fat diet and chemical mutagenesis to make a time line of mouse primary hepatocellular carcinoma model; B. normal control group, high fat diet and chemical mutagenesis mice primary hepatocellular carcinoma group and reversal after GGOH anaplerosis; the degree of malignancy of hepatocellular carcinoma in three groups of mice in C-E.B was compared and statistical analysis of the number and volume of tumors was performed.

Similarly, in the hepatoma cell lines Huh7 and HepG2, GGPP treatment could also significantly inhibit the viability and proliferation of hepatoma cells (fig. 16). There was no significant change in the viability of both cells when they were transformed into FBP1-WT and FBP1-R50N in Huh7 or HepG 2; while the combination of both FBP1-WT and FBP1-R50N with GGPP treatment significantly decreased the FBP1-WT/GGPP group compared to FBP1-R50N/GGPP, indicating that the FBP1-R50 site is critical for its response to GGPP stimulation (FIG. 13). FIG. 16 is a graph showing that GGPP treatment of the present invention significantly inhibited the viability and proliferation of hepatoma cells; GGPP treatment obviously inhibits the activity and proliferation of liver cancer cells Huh 7; GGPP treatment obviously inhibits the activity and proliferation of liver cancer cells HepG 2. FIG. 13 is a graph showing that mutations at FBP1-R50 inhibit the activity of FBP1 in inhibiting hepatoma cells in response to GGPP stimulation; r50 reduces the ability of FBP1 to inhibit the viability and proliferation of hepatoma cells Huh7 in response to GGPP stimulation; the mutation of C-D.R50 reduces the ability of FBP1 to inhibit the viability and proliferation of hepatoma cells HepG2 in response to GGPP stimulation.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the foregoing description only for the purpose of illustrating the principles of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims, specification, and equivalents thereof.