Linear antigen peptide for diagnosing schizophrenia and its application, kit and its application

Abstract

The present invention provides a linear antigen peptide for diagnosing schizophrenia and its application, a kit and its application, and relates to the field of schizophrenia diagnosis. The linear antigen peptide is used to bind to a schizophrenia diagnostic marker, and the amino acid sequence of the linear antigen peptide includes at least one of SEQ ID NO. 1 to 5. The technical solution of the present invention detects the proportion of antibodies corresponding to the antigens in the sample by using at least one peptide segment containing FURIN antigen, MOB4 antigen, PDIA3 antigen, MAD1L1 antigen and CACNA1C antigen to diagnose schizophrenia. Compared with the normal person, the expression content is low, which means that it meets the diagnosis of schizophrenia.

Description

Technical Field

[0001] The present invention relates to the field of schizophrenia diagnosis, and in particular to a linear antigen peptide and application thereof, a kit and application thereof for diagnosing schizophrenia. Background Art

[0002] Schizophrenia is a serious mental illness characterized by disorders of perception, thinking, emotion and behavior. Common symptoms include hallucinations, delusions, disorganized speech, social withdrawal and impaired cognitive function.

[0003] When a person first experiences these symptoms and is diagnosed with schizophrenia, if he or she has not yet started using antipsychotic drugs or other forms of treatment, he or she is considered a drug-naïve First-Episode Schizophrenia (drug-naïve FES) patient. Early identification and prompt treatment are very important for such patients, as early intervention can significantly affect the long-term prognosis of the disease, reduce the severity of symptoms, improve quality of life, and may slow or stop the progression of the disease.

[0004] At present, the existing diagnostic method for schizophrenia is to conduct multi-angle evaluation through blood tests, urine tests, electroencephalograms, neurological tests and genetic tests to exclude possibilities other than schizophrenia, such as metabolic disorders, drug abuse, abnormal brain structure, etc., thereby indirectly diagnosing schizophrenia. Schizophrenia cannot be diagnosed directly, the diagnosis time is long, and the diagnostic results are indirect and inaccurate. Summary of the invention

[0005] The main purpose of the present invention is to propose a linear antigen peptide and its application, a kit and its application for diagnosing schizophrenia, aiming to provide a path for diagnosing schizophrenia, as well as an antigen peptide and a kit for diagnosing schizophrenia.

[0006] To achieve the above object, the present invention provides a linear antigen peptide for diagnosing schizophrenia, wherein the linear antigen peptide is used to bind to a diagnostic marker for schizophrenia, and the amino acid sequence of the linear antigen peptide includes at least one of SEQ ID NO.1 to 5.

[0007] In one embodiment, the amino acid sequence of the linear antigenic peptide includes the amino acid sequence shown in SEQ ID NO.1, and the linear antigenic peptide is used to specifically bind to the anti-human FURIN antibody; and / or,

[0008] The amino acid sequence of the linear antigen peptide includes the amino acid sequence shown in SEQ ID NO.2, and the linear antigen peptide is used to specifically bind to the anti-human MOB4 antibody; and / or,

[0009] The amino acid sequence of the linear antigen peptide includes the amino acid sequence shown in SEQ ID NO.3, and the linear antigen peptide is used to specifically bind to the anti-human PDIA3 antibody; and / or,

[0010] The amino acid sequence of the linear antigen peptide includes the amino acid sequence shown in SEQ ID NO.4, and the linear antigen peptide is used to specifically bind to the anti-human MAD1L1 antibody; and / or,

[0011] The amino acid sequence of the linear antigen peptide includes the amino acid sequence shown in SEQ ID NO.5, and the linear antigen peptide is used for specifically binding to the anti-human CACNA1C antibody.

[0012] The present invention also provides a use of a linear antigen peptide in preparing a kit for diagnosing schizophrenia, wherein the linear antigen peptide includes the linear antigen peptide as described above.

[0013] In one embodiment, the kit is an ELISA-based detection kit.

[0014] The present invention also provides a kit for diagnosing schizophrenia, wherein the kit comprises the aforementioned linear antigen peptide.

[0015] In one embodiment, the kit is a kit based on ELISA detection;

[0016] The kit is used for diagnosing schizophrenia, and comprises a washing solution, a diluent, a developing solution, a stopping solution and a detection plate. The detection plate is coated with a linear antigen peptide, and the amino acid sequence of the linear antigen peptide comprises at least one of SEQ ID NOs. 1 to 5.

[0017] The present invention also provides a kit for use in diagnosing schizophrenia, wherein the kit comprises the kit as described above.

[0018] In one embodiment, the application method comprises the following steps:

[0019] S100. After washing the detection plate with a washing solution, add the sample to be tested, incubate, wash the plate, add the secondary antibody diluent, and incubate in the dark;

[0020] S200. After washing the plate, add the color developing solution, incubate in dark place, add the stop solution, and place in a microplate reader to measure the optical density of the sample to be tested;

[0021] S300. Calculating the specific binding rate of the diagnostic marker for schizophrenia in the sample to be tested according to the optical density of the sample to be tested;

[0022] Wherein, the sample to be tested includes a plasma sample.

[0023] In one embodiment, in step S300, the specific binding rate is calculated as follows:

[0024] ,

[0025] Among them, SBR is the specific binding rate of schizophrenia diagnostic markers, OD sample is the absorbance of the sample to be tested, OD PC is the absorbance of the positive control, OD NC is the absorbance of the blank control.

[0026] The technical solution of the present invention adopts at least one of anti-human FURIN antibody, anti-human MOB4 antibody, anti-human PDIA3 antibody, anti-human MAD1L1 antibody and anti-human CACNA1C antibody as a diagnostic marker for schizophrenia. At least one peptide segment containing FURIN antigen, MOB4 antigen, PDIA3 antigen, MAD1L1 antigen and CACNA1C antigen can be used to detect the proportion of antibodies corresponding to the antigens in the sample to diagnose schizophrenia. A lower expression level compared to that of normal people indicates that it meets the diagnosis of schizophrenia. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 This is a ROC curve diagram of the diagnostic model constructed by combining linear antigen peptides provided in Examples 1 to 5 of the present invention.

[0029] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0030] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0031] It should be noted that, in the embodiments, those without specifying specific conditions are carried out according to normal conditions or conditions recommended by the manufacturer. Those without specifying the manufacturer of reagents or instruments used are conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes, and "A and / or B" is taken as an example, including schemes A, B, or A and B that meet the same time. In addition, the technical schemes between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in the field to achieve. When the combination of the technical schemes is contradictory or cannot be achieved, it should be considered that the combination of such technical schemes does not exist, and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work, all belong to the scope of protection of the present invention.

[0032] At present, the existing diagnostic method for schizophrenia is to conduct multi-angle evaluation through blood tests, urine tests, electroencephalograms, neurological tests and genetic tests to exclude possibilities other than schizophrenia, such as metabolic disorders, drug abuse, abnormal brain structure, etc., thereby indirectly diagnosing schizophrenia. Schizophrenia cannot be diagnosed directly, the diagnosis time is long, and the diagnostic results are indirect and inaccurate.

[0033] In view of this, the present invention proposes a linear antigen peptide for diagnosing schizophrenia, wherein the linear antigen peptide is used to bind to a diagnostic marker for schizophrenia, and the amino acid sequence of the linear antigen peptide includes at least one of SEQ ID NOs. 1 to 5.

[0034] SEQ ID NO. 1: CKGLPPEAWQEECPSDSEEDEGRGERRH.

[0035] SEQ ID NO. 2: RRNRPGTKAQDFYNWPDESFEMHC.

[0036] SEQ ID NO. 3: DILQREATNPPVIQEEKPKKKKKAQEDC.

[0037] SEQ ID NO. 4: VEGGSGLDISTSAPGSLQMQYQHC.

[0038] SEQ ID NO. 5: CEENHQGSNYGSPRPAHANMNANAA.

[0039] The technical solution of the present invention adopts at least one of anti-human FURIN antibody, anti-human MOB4 antibody, anti-human PDIA3 antibody, anti-human MAD1L1 antibody and anti-human CACNA1C antibody as a diagnostic marker for schizophrenia. At least one peptide segment containing FURIN antigen, MOB4 antigen, PDIA3 antigen, MAD1L1 antigen and CACNA1C antigen can be used to detect the proportion of antibodies corresponding to the antigens in the sample to diagnose schizophrenia. A lower expression level compared to that of normal people indicates that it meets the diagnosis of schizophrenia.

[0040] In one embodiment, the amino acid sequence of the linear antigenic peptide includes the amino acid sequence shown in SEQ ID NO.1, and the linear antigenic peptide is used to specifically bind to an anti-human FURIN antibody; and / or, the amino acid sequence of the linear antigenic peptide includes the amino acid sequence shown in SEQ ID NO.2, and the linear antigenic peptide is used to specifically bind to an anti-human MOB4 antibody; and / or, the amino acid sequence of the linear antigenic peptide includes the amino acid sequence shown in SEQ ID NO.3, and the linear antigenic peptide is used to specifically bind to an anti-human PDIA3 antibody; and / or, the amino acid sequence of the linear antigenic peptide includes the amino acid sequence shown in SEQ ID NO.4, and the linear antigenic peptide is used to specifically bind to an anti-human MAD1L1 antibody; and / or, the amino acid sequence of the linear antigenic peptide includes the amino acid sequence shown in SEQ ID NO.5, and the linear antigenic peptide is used to specifically bind to an anti-human CACNA1C antibody.

[0041] The present invention also provides a use of a linear antigen peptide in preparing a kit for diagnosing schizophrenia, wherein the linear antigen peptide includes the linear antigen peptide as described above.

[0042] In one embodiment, the kit is an ELISA-based detection kit.

[0043] The present invention also provides a kit for diagnosing schizophrenia, wherein the kit comprises the aforementioned linear antigen peptide.

[0044] In one embodiment, the kit is a kit based on ELISA detection; the kit is used to diagnose schizophrenia, the kit includes a washing solution, a diluent, a color developing solution, a stop solution and a detection plate, the detection plate is coated with a linear antigen peptide, and the amino acid sequence of the linear antigen peptide includes at least one of SEQ ID NO.1 to 5.

[0045] The present invention also provides a kit for use in diagnosing schizophrenia, wherein the kit comprises the kit as described above.

[0046] In one embodiment, the washing solution comprises Tween 20 and PBS buffer; and / or, the diluent comprises Tween 20 and fetal bovine serum buffer.

[0047] The technical solution of the present invention can effectively remove unbound proteins and other nonspecific binders by adopting Tween 20, thereby reducing background signals and improving the specificity and accuracy of detection; fetal bovine serum (FBS) is used as a sample diluent to reduce nonspecific adsorption occurring during the antigen-antibody binding process.

[0048] The present invention also proposes a method for preparing a kit, comprising the following steps: S10. preparing a new well plate, a washing solution and a blocking solution, setting a nonspecific reference well, a positive control reference well, a quality control reference well, a detection well and a blank control well on the well plate, coating the positive control reference well, the quality control reference well, the blank control well, the positive control reference well and the detection well with EMB linear peptide antigens, adding a coating solution to the nonspecific reference well, and incubating at 2°C to 6°C for 20 to 30 h; S20. after washing and buckling the plate, adding a blocking solution, incubating at 36°C to 38°C for 100 min to 150 min, washing and buckling the plate again, and drying to obtain a detection well plate.

[0049] The technical solution of the present invention can effectively evaluate nonspecific binding, reduce background interference and improve detection sensitivity by adopting positive control reference wells, quality control reference wells, blank control reference wells and nonspecific reference wells; long-term incubation under low temperature conditions of 2°C to 6°C can ensure stable coating of EMB linear peptide antigens, and blocking treatment at 36°C to 38°C helps to form a stable blocking layer, thereby improving the overall stability of the well plate.

[0050] The present invention also provides a kit for use in diagnosing schizophrenia, wherein the kit comprises the kit as described above.

[0051] In one embodiment, the application method includes the following steps: S100. After washing the detection well plate with a washing solution, add the sample to be tested, incubate, wash the plate, add the secondary antibody diluent, and incubate in the dark; S200. After the plate is pressed and washed, add the color developing solution, incubate in the dark, add the stop solution, and place it in an ELISA instrument to measure the optical density of the sample to be tested; S300. Calculate the specific binding rate of the schizophrenia diagnostic marker in the sample to be tested based on the optical density of the sample to be tested; wherein, the sample to be tested includes a plasma sample.

[0052] The technical solution of the present invention determines the specific binding rate by calculating the optical density ratio of the reference well and the detection well, which can more accurately evaluate the content of the schizophrenia diagnostic marker in the sample to be tested, thereby providing a reliable basis for diagnosing schizophrenia.

[0053] In one embodiment, in step S300, the specific binding rate is calculated as follows:

[0054] ,

[0055] Among them, SBR is the specific binding rate of schizophrenia diagnostic markers, OD sample is the absorbance of the sample to be tested, OD PC is the absorbance of the positive control, OD NC is the absorbance of the blank control well.

[0056] The technical solution of the present invention can effectively improve the sensitivity and accuracy of detection, reduce background interference, simplify the operation process, and improve the accuracy of result interpretation by accurately controlling experimental conditions and operation processes.

[0057] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention, and are not used to limit the present invention.

[0058] The technical solution of the present invention uses the following solution:

[0059] Washing solution: 0.01 M PBS containing 0.1% Tween-20;

[0060] Blocking solution: containing 5% bovine serum albumin (BSA);

[0061] Diluent: 10% FBS containing 0.1% Tween-20;

[0062] Coating solution: 0.05 mol / L carbonate buffer (pH 9.6), including 1.5 g / L sodium carbonate and 2.92 g / L sodium bicarbonate;

[0063] Color developing solution: 3,3',5,5'-tetramethylbenzidine (TMB) (Solybdenum, product number PR1210);

[0064] Stop solution: 12% sulfuric acid.

[0065] Goat anti-human IgG Fc (HRP) (Abcam Catalog No. ab98624) original concentration 1 ug / ul;

[0066] Human IgG (Sigma-Aldrich Product No.: I4506) was stored at 20 mg / ml, and 10 ul was dispensed into each tube and used after dilution 100 times.

[0067] Quality control blood samples: 20 healthy controls were randomly selected, with 300ul plasma from each person. The plasma of the 20 people was fully mixed and then divided into 10ul tubes and frozen at -80 degrees Celsius, and then diluted 100 times before use.

[0068] The EMB and GPM6A linear antigen peptides were produced by solid phase chemical synthesis, with a purity requirement of more than 95% (commissioned to Shanghai Shenggong Company for synthesis). The synthesized linear antigen peptides were coupled with KLH, dissolved into a 1 mg / ml solution using an antibody protective agent and stored at 4°C. Diluted to the working concentration (250 times, 20 μg / mL) with coating solution before use.

[0069] Example 1

[0070] This example provides a design of an autoantigenic epitope on the surface of a FURIN protein and the preparation of an epitope linear antigen peptide:

[0071] The HLA-II specific epitopes of FURIN protein were predicted using the current online prediction platform for antigenic epitopes of human diseases (http: / / www .iedb.org / ). In this study, a linear FURIN antigenic epitope that specifically binds to anti-human FURIN antibodies was designed, and its amino acid sequence from N-terminus to C-terminus is: CKGLPPEAWQEECPSDSEEDEGRGERRH (SEQ ID NO.1).

[0072] Example 2

[0073] This example provides a design of an autoantigenic epitope on the surface of a MOB4 protein and the preparation of an epitope linear antigen peptide:

[0074] The HLA-II specific epitopes of MOB4 protein were predicted using the current online prediction platform for antigenic epitopes of human diseases (http: / / www .iedb.org / ). In this study, a linear MOB4 antigenic epitope that specifically binds to anti-human MOB4 antibodies was designed, and its amino acid sequence from N-terminus to C-terminus is:

[0075] RRNRPGTKAQDFYNWPDESFEMHC (SEQ ID NO. 2).

[0076] Example 3

[0077] This example provides a design of an autoantigenic epitope on the surface of a PDIA3 protein and the preparation of an epitope linear antigen peptide:

[0078] The HLA-II specific epitopes of PDIA3 protein were predicted using the current online prediction platform for antigenic epitopes of human diseases (http: / / www .iedb.org / ). In this study, a linear epitope of PDIA3 was designed for specific binding with anti-human PDIA3 antibodies. Its amino acid sequence from N-terminus to C-terminus is:

[0079] DILQREATNPPVIQEEKPKKKKKAQEDC (SEQ ID NO. 3).

[0080] Example 4

[0081] This example provides a design of an autoantigenic epitope on the surface of a MAD1L1 protein and the preparation of an epitope linear antigen peptide:

[0082] The HLA-II specific epitopes of MAD1L1 protein were predicted using the current online prediction platform for antigenic epitopes of human diseases (http: / / www .iedb.org / ). In this study, a linear epitope of MAD1L1 was designed for specific binding with anti-human MAD1L1 antibodies. Its amino acid sequence from N-terminus to C-terminus is:

[0083] VEGGSGLDISTSAPGSLQMQYQHC (SEQ ID NO. 4).

[0084] Example 5

[0085] This example provides a design of an autoantigenic epitope on the surface of a CACNA1C protein and the preparation of an epitope linear antigen peptide:

[0086] The HLA-II specific epitopes of CACNA1C protein were predicted using the current online prediction platform for antigenic epitopes of human diseases (http: / / www .iedb.org / ). In this study, a linear epitope of CACNA1C was designed for specific binding with anti-human CACNA1C antibodies. Its amino acid sequence from N-terminus to C-terminus is:

[0087] CEENHQGSNYGSPRPAHANMNANAAAA (SEQ ID NO. 5).

[0088] Example 6

[0089] This embodiment provides a kit, the preparation method of which comprises the following steps:

[0090] Prepare a 96-well plate to coat the FURIN linear peptide antigen coupled to KLH at a coating concentration of 20 ng / ml, 100uL / well. Except for wells H11 and H12 of each plate, only coating solution is added without antigen, indicating a signal of nonspecific adsorption. The coated 96-well plate is sealed and incubated at 4°C overnight.

[0091] After draining the liquid in the plate, add 200 ul of washing solution and shake on a shaker at 800 rpm / min for 1 min. Repeat the washing process twice, then drain the 96-well plate and add 300 uL / well of blocking solution and incubate at 37°C for 2 hours.

[0092] After draining the liquid in the plate, add 300 ul of washing solution and shake on a shaker at 800 rpm / min. After shaking for 1 min, drain the liquid in the plate and put it into a drying oven at 40℃ for 3h to dry the 96-well plate. After sealing, store it at 4℃.

[0093] Example 7

[0094] This embodiment provides a kit, the preparation method of which is similar to that of Example 6, except that the FURIN linear peptide antigen is replaced by the MOB4 linear peptide antigen.

[0095] Example 8

[0096] This embodiment provides a kit, the preparation method of which is similar to that of Example 6, except that the FURIN linear peptide antigen is replaced by the PDIA3 linear peptide antigen.

[0097] Example 9

[0098] This embodiment provides a kit, and its preparation method is similar to that of Example 6, except that the FURIN linear peptide antigen is replaced by the MAD1L1 linear peptide antigen.

[0099] Example 10

[0100] This embodiment provides a kit, the preparation method of which is similar to that of Example 6, except that the FURIN linear peptide antigen is replaced by the CACNA1C linear peptide antigen.

[0101] Embodiment 11

[0102] This embodiment provides an application of a kit in diagnosing schizophrenia. The levels of FURIN, MOB4, PDIA3, MAD1L1 and CACNA1C autoimmune antibodies in the peripheral plasma of the subjects are measured using an enzyme-linked immunosorbent assay (ELISA) detection method developed by our laboratory.

[0103] Using the kit provided in Examples 6 to 10, the application comprises the following steps:

[0104] 1. Select the well plate of the kit provided in each embodiment 6 to 10, add 300 ul of washing solution after stabilization at room temperature, shake on a shaker at 800 rpm / min for 1 min, wash the plate twice, and perform duplicate loading of samples in the 96-well plate, wherein well A1 and well A2 are used as blank control reference wells, well H11 and well H12 are used as nonspecific reference wells, well G11 and well G12 are used as positive control reference wells, and well F11 and well F12 are used as quality control reference wells; add 50 ul / well of human IgG reagent to well H11, well H12, well G11 and well G12, add 50 ul / well of primary antibody diluent to well A1 and well A2 as blank control, well H11 and well H12 as nonspecific control, well G11 and well G12 as positive control; add 50 ul / well of diluted quality control sample to well F11 and well F12 as quality control reference wells; add 50 ul / well of diluted sample to be tested to other wells ul / well, incubate at 37℃ for 2 h.

[0105] 2. After draining the liquid in the plate, add 300ul of washing solution and shake on a shaker at 800rpm / min for 1min. Repeat the washing process 5 times and then add the diluent containing the secondary antibody. The secondary antibody is goat anti-human IgG Fc labeled with horseradish peroxidase. The dilution ratio is 1:40000, 100ul / well, and incubate at room temperature in the dark for 1h.

[0106] 3. After draining the liquid in the plate, add 300ul of washing solution and shake on a shaker at 800rpm / min for 1min. Repeat the washing process 5 times and add 100ul / well of colorimetric solution. After 10min at room temperature and away from light, add 50ul / well of stop solution. Within 10 minutes, measure the optical density (OD) of each well at 450nm with an ELISA reader, with a reference wavelength of 620nm. Then all samples were tested in duplicate, and the specific binding rate (SBR) of each sample was calculated using the following formula:

[0107] .

[0108] In this embodiment, the addition of samples in the 96-well plate is shown in Table 1.

[0109] Table 1 Sample addition to the 96-well plate in Example 2

[0110] 96-well plate 1 2 3 4 5 6 7 8 9 10 11 12 A NC NC 201 201 D101 D101 101 101 D20_1 D20_1 N2001 N2001 B 1 1 202 202 D102 D102 102 102 D20_2 D20_2 N2002 N2002 C 2 2 203 203 D103 D103 103 103 D20_3 D20_3 N2003 N2003 D 3 3 204 204 D104 D104 104 104 D20_4 D20_4 N2004 N2004 E 4 4 205 205 D105 D105 105 105 D20_5 D20_5 N2005 N2005 F 5 5 206 206 D106 D106 106 106 D20_6 D20_6 QC QC G 6 6 207 207 D107 D107 107 107 D20_7 D20_7 PC PC H 7 7 208 208 D108 D108 108 108 D20_8 D20_8 NSC NSC

[0111] In Table 1, NC represents blank control group, QC represents quality control group, PC represents positive control group, NSC represents nonspecific control group, and 1-7, 201-208, D101-D108, D20_1-D20_8, and N2001-N2005 are all diluted samples.

[0112] Performance Testing

[0113] The detection method used in this study is an antigen-antibody immune response detection based on the ELISA principle. To ensure its applicability, the team verified the repeatability of the detection platform during the experiment. In Example 11, the same quality control sample QC was added to each 96-well plate in the experimental detection. By calculating the coefficient of variation CV of the QC between all plates, the repeatability of the experimental detection can be known. Each linear antigen peptide epitope was tested on 7 96-well plates. The results showed that the batch difference of the FURIN kit in Example 6 was 5.64%, the batch difference of the MOB4 kit in Example 7 was 5.33%, the batch difference of the PDIA3 kit in Example 8 was 2.72%, the batch difference of the MAD1L1 kit in Example 9 was 10.91%, and the batch difference of the CACNA1C kit in Example 10 was 18.65%. The inter-batch coefficient of variation of the two is much lower than the CV required by the general detection kit, which is not higher than 20%. It shows that the detection technology has high repeatability and can be used for the research and development of corresponding detection kits.

[0114] The application test was carried out in the plasma of 60 normal people and 155 first-episode drug-free schizophrenia patients. The test results are shown in Table 2.

[0115] Table 2 Basic information and test results of the first-episode schizophrenia test kit

[0116]

[0117] According to Table 2, compared with the normal population, the anti-human FURIN antibodies, anti-human MOB4 antibodies, anti-human PDIA3 antibodies and anti-human MAD1L1 antibodies of the first-onset drug-naive schizophrenia patients were significantly reduced, indicating that the FURIN linear antigen peptide, MOB4 linear antigen peptide, PDIA3 linear antigen peptide and MAD1L1 linear antigen peptide can be used alone to diagnose schizophrenia, and the CACNA1C linear antigen peptide can be combined with one or more of the above four linear antigen peptides to further improve the accuracy of diagnosing schizophrenia.

[0118] Schizophrenia and normal control groups were set as dependent variables, gender and age were set as covariates, and anti-human FURIN antibody, anti-human MOB4 antibody, anti-human PDIA3 antibody, anti-human MAD1L1 antibody, and anti-human CACNA1C antibody were used as independent variables to construct binary logistic regression. Before building the model, all antibodies were decentralized to avoid collinearity, which would lead to poor model interpretability. Due to the imbalanced sample size, SMOTE resampling was used to balance the sample during model construction, and ten-fold cross validation was used, repeated 1000 times, to make the model more stable. Figure 1As shown in the figure, the AUC of the final model was 0.778, P < 0.001. The sensitivity of the model was 0.78, the specificity was 0.69, the positive predictive value was 0.49, and the negative predictive value was 0.89.

[0119] According to the above statistical analysis results, compared with normal people, the schizophrenia diagnostic model constructed using the combined antibody strategy (including anti-human FURIN, anti-human MOB4, anti-human PDIA3, anti-human MAD1L1 and anti-human CACNA1C antibodies) can significantly distinguish schizophrenia patients. The five linear antigen peptide epitopes identified in this study and the experimental detection method developed can effectively detect autoimmune antibodies in the peripheral plasma of schizophrenia patients, providing a potential application tool for the development of clinical detection kits for schizophrenia patients.

[0120] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A linear antigen peptide for diagnosing schizophrenia, characterized in that: The linear antigen peptide is used to bind to a diagnostic marker for schizophrenia, and the linear antigen peptide consists of five polypeptides, and the amino acid sequences of the five polypeptides are the amino acid sequences of SEQ ID NO.1 to 5 respectively; The amino acid sequence shown in SEQ ID NO.1 is used to specifically bind to the anti-human FURIN antibody; The amino acid sequence shown in SEQ ID NO.2 is used to specifically bind to the anti-human MOB4 antibody; The amino acid sequence shown in SEQ ID NO.3 is used to specifically bind to anti-human PDIA3 antibodies; The amino acid sequence shown in SEQ ID NO.4 is used to specifically bind to the anti-human MAD1L1 antibody; The amino acid sequence shown in SEQ ID NO.5 is used to specifically bind to the anti-human CACNA1C antibody.

2. Use of a linear antigen peptide in the preparation of a kit for diagnosing schizophrenia, characterized in that The linear antigenic peptide comprises the linear antigenic peptide according to claim 1.

3. The use according to claim 2, characterized in that The kit is a kit based on ELISA detection.

4. A kit for diagnosing schizophrenia, characterized in that: The kit comprises the linear antigen peptide as claimed in claim 1.

5. The kit for diagnosing schizophrenia according to claim 4, characterized in that The kit is a kit based on ELISA detection; The kit is used for diagnosing schizophrenia, and comprises a washing solution, a diluent, a color developing solution, a stop solution and a detection well plate, wherein the detection well plate is coated with the linear antigen peptide.

Images