阅读说明：本技术 富含亮氨酸的α2糖蛋白组合物 (Leucine-rich alpha 2 glycoprotein compositions ) 是由 高山茂雄 仲哲治 世良田聪 于 2019-10-08 设计创作，主要内容包括：本发明的一个目的是提供一种富含亮氨酸的α2糖蛋白组合物,其包含富含亮氨酸的α2糖蛋白并且具有优异的保存稳定性。本发明的该目的可以通过包含富含亮氨酸的α2糖蛋白并且具有7.0至9.3的pH的富含亮氨酸的α2糖蛋白组合物来实现。(An object of the present invention is to provide a leucine-rich α 2 glycoprotein composition, which comprises a leucine-rich α 2 glycoprotein and has excellent storage stability. This object of the invention can be achieved by a leucine rich alpha 2 glycoprotein composition comprising a leucine rich alpha 2 glycoprotein and having a pH of 7.0 to 9.3.)

1. A leucine rich alpha 2 glycoprotein composition comprising a leucine rich alpha 2 glycoprotein, wherein the pH of the composition is between 7.0 and 9.3.

2. The leucine rich α 2 glycoprotein composition according to claim 1, which is a calibration sample solution for the determination of leucine rich α 2 glycoprotein.

3. Leucine rich alpha 2 glycoprotein composition according to claim 1 or 2, filled in a preservation container.

4. A leucine rich α 2 glycoprotein composition according to any of claims 1 to 3, wherein the pH of the composition is between 7.8 and 9.0.

5. Leucine rich alpha 2 glycoprotein composition according to any of the claims 1 to 4, wherein the salt concentration of the composition is between 200mM and 800 mM.

6. The leucine rich α 2 glycoprotein composition of claim 5, wherein the salt is a metal salt.

7. A method of assaying for leucine rich alpha 2 glycoprotein comprising:

use of a leucine rich alpha 2 glycoprotein composition according to any of the claims 1 to 6.

8. A kit for assaying a leucine rich α 2 glycoprotein comprising a leucine rich α 2 glycoprotein composition according to any of claims 1 to 6.

9. A method for the storage stabilization of a leucine rich α 2 glycoprotein, comprising:

contacting the leucine rich alpha 2 glycoprotein with a solvent having a pH of 7.0 to 9.3.

10. The method for storage-stabilizing leucine rich α 2 glycoprotein according to claim 9, wherein the pH of the solvent is 7.8 to 9.0.

11. The method for storage-stabilizing leucine rich α 2 glycoprotein according to claim 9 or 10, wherein the salt concentration in the solvent is 200mM to 800 mM.

12. The method for storage-stabilizing leucine rich α 2 glycoprotein according to any of claims 9 to 11, wherein the salt is a metal salt.

Technical Field

The present invention relates to leucine rich alpha 2 glycoprotein compositions. More particularly, the present invention relates to a composition that can stably preserve a leucine-rich α 2 glycoprotein for a long period of time.

Background

Leucine-rich α 2 glycoprotein (hereinafter sometimes referred to as LRG) is one of serum proteins. LRG is reported to be a glycoprotein of about 50kDa, secreted by neutrophils (non-patent document 1).

Recently, the correlation of LRG with specific diseases in biological samples has been investigated. For example, patent document 1 reports that detecting LRG in a biological sample is useful for detecting autoimmune diseases such as Behcet's disease.

In order to quantitatively determine a component to be measured in a biological sample, a calibration sample must be used. The calibration sample is a sample containing a component to be measured, and is used as an internal standard, a concentration calibration standard (calibrator), or the like. In order to obtain an accurate quantitative value, a calibration sample that remains stable against the passage of time or temperature is required. That is, it is believed that the measured value is also affected when the component to be measured in the calibration sample is decomposed and/or denatured during storage. For the quantitative determination of LRG, a method using enzyme-linked immunosorbent assay (ELISA) or the like has been known so far, but a calibration sample has not been examined.

List of citations

Patent document

Patent document 1: JP-A-2010-286279

Non-patent document

Non-patent document 1: j Leukoc biol.200272 (3): 478-85.2002

Disclosure of Invention

Technical problem

The inventors tried to produce a calibration sample solution containing LRG. As a result, it was found that when LRG was added to a solution having a pH of less than 7, the stability of LRG was poor, and LRG was gradually decomposed and lost with time.

It is an object of the present invention to provide a leucine-rich α 2 glycoprotein composition comprising a leucine-rich α 2 glycoprotein and having a high storage stability.

Means for solving the problems

As a result of further studies, the inventors found that the stability of LRG is improved when the pH of a solution containing LRG is maintained within a specific range. It was also found that the stability of LRG was further improved when the salt concentration of the solution was within a specific range. The present invention is based on these findings.

Specifically, the present invention is as follows:

<1> a leucine-rich alpha 2 glycoprotein composition comprising a leucine-rich alpha 2 glycoprotein, wherein the pH of the composition is between 7.0 and 9.3,

<2> the leucine rich alpha 2 glycoprotein composition according to <1>, which is a calibration sample solution for the determination of leucine rich alpha 2 glycoprotein,

<3> the leucine rich alpha 2 glycoprotein composition according to <1> or <2>, which is filled in a storage container,

<4> the leucine rich alpha 2 glycoprotein composition according to any of <1> to <3>, wherein the pH of the composition is 7.8 to 9.0,

<5> the leucine rich alpha 2 glycoprotein composition according to any of <1> to <4>, wherein the salt concentration of the composition is 200mM to 800mM,

<6> the leucine rich alpha 2 glycoprotein composition according to <5>, wherein the salt is a metal salt,

<7> a method for assaying leucine-rich α 2 glycoprotein, comprising:

using the leucine-rich alpha 2 glycoprotein composition according to any of <1> to <6>,

<8> a kit for assaying a leucine-rich alpha 2 glycoprotein comprising the leucine-rich alpha 2 glycoprotein composition according to any one of claims <1> to <6>,

<9> a method for storage-stabilizing a leucine-rich α 2 glycoprotein, comprising:

contacting the leucine-rich alpha 2 glycoprotein with a solvent having a pH of 7.0 to 9.3,

<10> the method for storage-stabilizing a leucine-rich α 2 glycoprotein according to <9>, wherein the pH of the solvent is 7.8 to 9.0,

<11> the method for storage-stabilizing leucine-rich α 2 glycoprotein according to <9> or <10>, wherein the salt concentration in the solvent is from 200mM to 800mM, and

<12> the storage stabilization method of leucine rich α 2 glycoprotein according to any of <9> to <11>, wherein the salt is a metal salt.

Advantageous effects of the invention

According to the present invention, an LRG-containing composition containing a leucine-rich α 2 glycoprotein and having excellent storage stability can be provided, and particularly, an LRG-containing calibration sample can be provided. Therefore, according to the present invention, LRG in a biological sample can be accurately quantitatively determined, and a disease can be accurately diagnosed.

Drawings

FIG. 1 shows a graph of the LRG amount over time for solutions with different pH values, where the initial value is considered to be 100%.

Fig. 2 shows a graph of the LRG amount over time for solutions with different salt concentrations, where the initial value is considered to be 100%.

FIG. 3 shows a graph of the LRG amount over time for solutions with different pH values, where the initial value is considered to be 100%.

Detailed Description

(leucine-rich alpha 2 glycoprotein)

Leucine rich alpha 2 glycoprotein or LRG is a glycoprotein of about 50 kDa. LRG is one of the serum proteins, said to be contained in the serum of healthy individuals at about 3.0. mu.g/mL. LRG is reported to be secreted by neutrophils. In recent years, correlation between changes in the amount of LRG in vivo and various diseases such as tuberculosis and tumor has been studied, and accurate measurement of the amount of LRG in vivo is required for accurate diagnosis of these diseases.

LRG can be determined using known methods such as immunological methods. Immunological methods include ELISA, enzyme immunoassay, surface plasmon resonance, latex agglutination immunoassay (LTIA), chemiluminescent immunoassay, electrochemiluminescent immunoassay, fluorescent antibody technology, radioimmunoassay, immunoprecipitation, western blot, immunochromatography, High Performance Liquid Chromatography (HPLC), and the like.

As the LRG contained in the composition of the present invention, commercially available LRG may be used, or LRG produced or purified by a user may be used. As the LRG contained in the composition of the present invention, LRG produced in vitro may be used, or LRG extracted from a living body may be used.

(pH)

In view of LRG stability, the pH of the leucine rich α 2 glycoprotein composition of the present invention is 7.0 to 9.3, preferably 7.0 to 9.0, more preferably 7.5 to 9.0, further preferably 7.8 to 9.0, and most preferably 8.0 to 9.0.

The pH can be adjusted using pH adjusters known to those skilled in the art, such as sodium hydroxide.

(salt concentration)

The salt concentration of the LRG composition of the invention is preferably 200mM to 800mM, more preferably 300mM to 700mM, most preferably 300mM to 600 mM. By keeping the salt concentration within this range, the stability of LRG can be further improved.

As the kind of salt contained in the LRG composition of the present invention, any known salt may be used, for example, metal salts (such as sodium salt, potassium salt and magnesium salt) and non-metal salts (such as ammonium salt and amine salt) may be used. Preferably, a metal salt is used, more preferably a sodium salt. To provide the sodium salt, sodium chloride is most preferably used. More than one salt may also be used in combination.

(leucine-rich alpha 2 glycoprotein compositions)

In the present specification, a leucine-rich α 2 glycoprotein composition (hereinafter, may be referred to as an LRG composition) refers to an LRG-containing solution for measuring LRG. The LRG compositions of the invention may be suitable for use as calibration sample solutions for LRG assays. In the present specification, the calibration sample solution refers to a sample solution containing a substance to be measured at a certain concentration, which is used for accurately measuring the substance to be measured, and the standard substance, the calibrator, the control, the internal standard substance, and the like are the calibration sample solution. The form for providing the LRG composition of the present invention is a form in a solution state prepared in advance by mixing LRG and a solvent having a pH of 7.0 to 9.3. Another form for providing the LRG composition of the present invention is a form in which the LRG and the solvent are separately prepared and mixed into a solution state before use.

The concentration of LRG in the LRG composition of the present invention may be 0.1 to 1000. mu.g/mL, 0.1 to 100. mu.g/mL, 1 to 50. mu.g/mL, or 1 to 30. mu.g/mL, although the concentration is not limited to this range.

In this regard, "using a leucine-rich α 2 glycoprotein composition" in the method for assaying a leucine-rich α 2 glycoprotein means that the leucine-rich α 2 glycoprotein composition is used for accurately assaying the leucine-rich α 2 glycoprotein, and means that, for example, the leucine-rich α 2 glycoprotein composition is used as a calibration sample solution (standard substance, calibrator, control, internal standard substance, etc.).

The composition of the LRG composition of the present invention is not particularly limited, except that the LRG composition contains LRG and has a pH of 7.0 to 9.3, as long as the effects of the present invention are not impaired and the use of LRG is not hindered. When LRG is measured by an immunological measuring method, the effect of the present invention should not be impaired, and all or part of reactions constituting the measuring system, such as antigen-antibody reaction, labeling reaction with biotin/avidin detection, and enzymatic reaction, should not be blocked. The components generally used in the immunological assay method may be appropriately selected and used according to the purpose, for example, buffers (e.g., acetic acid, citric acid, phosphoric acid, HEPES, MES, Tris, glycine, boric acid, carbonic acid, and Good's buffers), components for suppressing nonspecific reactions (nonionic surfactants, e.g., Tween20 and triton x-100, etc.), components for promoting antigen-antibody reactions (polymers, e.g., polyethylene glycol, polyvinylpyrrolidone, and phospholipid polymers, etc.), glycoproteins or peptides other than LRG (albumin, casein, etc.), amino acids, sugars (sucrose, cyclodextrin, etc.), preservatives (sodium azide, ProClin950, etc.), and the like.

The LRG composition of the invention may be stored in known containers. Materials that can be used for the preservation container of the LRG composition of the present invention may be polypropylene, polystyrene or glass, although the materials are not limited to these materials. The form of the preservation container may be hard or soft, and examples include ampoules, vials, soft bags, injection type containers, and the like.

The LRG may be produced by a cell expressing the LRG. Cells expressing LRG can be obtained by transforming a host with an expression vector containing DNA encoding LRG. The host cell may be a microbial cell, an insect cell, a mammalian cell, etc., and may be a prokaryotic cell or a eukaryotic cell. As the mammalian cells, there can be used, for example, HepG2 cells, HEK293 cells, HeLa cells, human FL cells, monkey COS-7 cells, monkey Vero cells, Chinese hamster ovary cells (hereinafter abbreviated as CHO cells), dhfr gene-knock-out CHO cells, mouse L cells, mouse AtT-20 cells, mouse myeloma cells, rat H4IIE-C3 cells, rat GH3 cells, and the like.

The plasmid obtained in the above manner can be introduced into a host cell by a conventional genetic engineering method. The transformant can be cultured by a general method for culturing a microorganism or culturing an insect cell or a mammalian cell. The LRG protein can be obtained by a combination of methods generally used for the isolation/purification of general proteins.

In the specification, "storage stabilization" or "stability improvement" means that the initial LRG value of a solution does not greatly differ from the measured value after storage because most of the LRG contained in the solution containing LRG is retained for a long time without decomposition or structural change. More specifically, for example, this means that, since 75% or more of LRG contained in a solution containing LRG is retained for 29 days without decomposition or structural change, the LRG value of the solution measured after being stored for 29 days at 37 ℃ is 75% or more of the initial value. The LRG value determined for the LRG composition of the invention after 29 days of storage at 37 ℃ is preferably 80% or more, more preferably 90% or more, further preferably 95% or more, most preferably 96% or more based on the initial amount. The LRG composition of the present invention has long-term stability even at a high temperature of 37 ℃, but LRG compositions stored at low or normal temperatures are not excluded from the scope of the present invention.

(biological samples for LRG assay)

The biological sample for measuring LRG is not particularly limited as long as LRG can be measured, and may be blood, serum, plasma, cerebrospinal fluid (CSF), urine, feces, or the like. Preferably, serum or plasma is used, and further preferably, serum is used. The organism or subject is not particularly limited as long as the organism or subject is a mammal and includes humans or animals (e.g., monkey, dog, cat, mouse, guinea pig, rat, hamster, horse, cow, and pig), preferably a human. If necessary, the biological sample may be subjected to appropriate pretreatment.

(leucine-rich alpha 2 glycoprotein assay kit)

Using the kit for measuring leucine-rich α 2 glycoprotein of the present invention (hereinafter sometimes referred to as LRG measurement kit), LRG can be accurately measured using an LRG composition. One example of an LRG assay kit is a kit using immunological methods. The LRG assay kit of the present invention may include a reagent for measuring LRG concentration in a human body by an immunological method. Immunological methods include ELISA, enzyme immunoassay, surface plasmon resonance, latex agglutination immunoassay (LTIA), chemiluminescent immunoassay, electrochemiluminescent immunoassay, fluorescent antibody technology, radioimmunoassay, immunoprecipitation, western blot, immunochromatography, High Performance Liquid Chromatography (HPLC), and the like. The immunological method is preferably latex agglutination immunoassay (LTIA).

The LRG assay kit of the present invention can be used for diagnosing autoimmune diseases, tuberculosis, tumors, inflammatory diseases and inflammatory bowel diseases (ulcerative colitis and Crohn's disease).

The LRG assay kit of the present invention may further include a user guide and the like. The kit may further comprise any of the constituent elements, such as buffers, stabilizers, sample diluents, pH adjusters and reaction vessels.

(method for preserving and stabilizing LRG composition)

The inventive method for preservation stabilization of an LRG composition comprises the step of contacting a leucine rich alpha 2 glycoprotein with a solvent having a pH of 7.0 to pH 9.3. The solvent is not particularly limited as long as the pH is 7.0 to 9.3. The solvent may contain a buffer such as HEPES, MES, CHES, and Tris, and the concentration of the buffer may be 1 to 1000 mM. In addition to adding LRG to a solvent having a pH of 7.0 to 9.3, "contacting" also includes adjusting the pH of a solution containing LRG having a pH of not 7.0 to 9.3 to 7.0 to 9.3.

Next, the present invention is specifically explained with reference to examples, but these examples do not limit the scope of the present invention. In the present specification,% represents% by weight unless otherwise specified.

Examples

Example 1 examination of the changes over time of the LRG amount of solutions having different pH values 1

After preparing LRG standard antigen solutions having different pH values, a preservation test was performed, and the LRG amount of the LRG standard antigen solution was checked with time. The effect of pH on the storage stability of LRG was therefore examined. The LRG used was produced using CHO (chinese hamster cell). Specifically, LRG is prepared by the following steps: the human LRG gene was introduced into CHO-K1 cells using a plasmid, the LRG gene-introduced CHO-K1 cells were cultured in a serum-free medium, and the human LRG recombinant protein was recovered from the culture supernatant.

An LRG standard antigen solution having the composition of table 1 below was prepared, and the pH was controlled to 7.5 or 8.0 using a 4N sodium hydroxide solution. The LRG standard antigen solution was stored at 37 ℃ for 29 days, and the change of the LRG amount with time was observed. Sample compositions and experimental results are shown in tables 1 and 2 and fig. 1.

[ Table 1]

Composition (I)	Concentration of
		Bovine serum albumin (BSA PF)	1％
HEPES	50mM
		Sodium chloride	150mM
TWEEN 20	0.01％
		EDTA3Na	5mM
ProClin950	0.05％
		Purified water	A necessary amount
LRG	10.0μg/mL

[ Table 2]

Sample numbering	pH of LRG standard antigen solution	Measurement after 29 days (initial measurement of 100%)
			1	7.5	81％
2	8.0	93％

After 29 days of storage at 37 ℃, the measurement value of the LRG standard antigen solution adjusted to pH 8.0 was 93% of the initial LRG amount. The measurement value of the LRG standard antigen solution adjusted to pH 7.5 was 81% of the initial LRG amount. Therefore, it was shown that when the pH of the LRG standard antigen solution was 8.0 instead of 7.5, the storage stability of LRG was excellent.

Example 2 examination of changes over time in the amount of LRG of solutions having different salt concentrations

In sample No. 2 prepared in example 1, the concentration of sodium chloride was changed from 150mM to 500mM, and a preservation test was performed. Therefore, the effect of salt concentration on the storage stability of LRG was examined. Sample compositions and experimental results are shown in table 3 and fig. 2.

[ Table 3]

Sample numbering	Salt concentration (mM)	Measurement after 29 days (initial measurement of 100%)
			2	150	93％
3	500	98％

The results showed that the LRG standard antigen solution with the salt concentration increased to 500mM can improve the storage stability of LRG compared with the LRG standard antigen solution with the salt concentration of 150 mM. The LRG standard antigen solution with a salt concentration of 150mM measured 93% of the initial LRG amount after 29 days of storage at 37 ℃, while the LRG standard antigen solution with a salt concentration of 500mM measured 98% of the initial LRG amount after 29 days of storage at 37 ℃.

EXAMPLE 3 examination of the changes over time in the amount of LRG of solutions having different pH values 2

An LRG standard antigen solution having the same composition as the sample prepared in example 1 was prepared, except that the buffer shown in table 4 below was used, and the pH was adjusted to 6.0, 7.0, 7.5, 8.0, 8.5, 9.0, or 9.5. The LRG standard antigen solution was stored at 37 ℃ for 29 days, and the change of the LRG amount with time was observed. Sample compositions and experimental results are shown in table 4 and fig. 3.

[ Table 4]

Sample numbering	Buffering agent	pH	Measurement after 29 days(initial measurement value: 100%)
				4	MOPS	6.0	52％
5	HEPES	7.0	75％
				6	HEPES	7.5	83％
7	HEPES	8.0	100％
				8	HEPES	8.5	100％
9	CHES	9.0	96％
				10	CHES	9.5	67％

From the above results, it was shown that when the pH of the LRG standard antigen solution was adjusted to 7.0 to 9.3, the storage stability of LRG was improved.

INDUSTRIAL APPLICABILITY

The leucine-rich alpha 2 glycoprotein composition of the present invention has excellent storage stability. Therefore, when the leucine rich α 2 glycoprotein composition of the present invention is used as a calibration sample, LRG in a biological sample can be accurately quantitatively determined, and a disease can be accurately diagnosed.