Characteristic peptides and their applications for the detection of fpgs and ggh protein expression

Abstract

The invention discloses characteristic peptide fragments for FPGS(folypolyglutamatesyn-thetase) and GGH(gamma-glutamyl hydrolase) protein expression quantity detection and application of the characteristic peptide fragments. A sequence of the characteristic peptide fragments for FPGS protein expression quantity detection is SGLQVEDLDR; and a sequence of the characteristic peptide fragments for GGHprotein expression quantity detection is YLESAGAR. A method for quantitative detection of FPGS and GGH protein expression quantities based on the characteristic peptide fragments includes the following steps that quantitative detection is conducted on the characteristic peptide fragments used for FPGS protein expression quantity detection and the characteristic peptide fragments used for GGH protein expression quantity detection through a liquid chromatography-mass spectrometry method or a QconCAT method so as to realize quantitative detection of the FPGS and GGH protein expression quantities. According to the characteristic peptide sequences, absolute quantitative analysis for FPGS and GGH can be realized simultaneously, efficiently, sensitively, accurately and repeatedly so as to realize clinical guidance for MTX(methotrexate) accurate administration in clinic.

Description

Technical field[0001]The present invention relates to the field of detection, and more particularly to the characteristic peptide segment and its application thereof for FPGS and GGH protein expression.Background technique[0002]Folypolyglutamatesyn-Tetase (FPGS) and GGH-Glutamyl Hydrolase, GGH mediated polygluttate in E effect cells in E effect cells Process and deterination process. Methodrexate polyglutamate, MTXPGS itself is self-sufficient, can be accumulated in intracellular accumulation, can be used for a long time to target, and therefore, the strength of MTX cytotrus is mainly dependent on intracellular MTXPGS. concentration. The FPGS and GGH-mediated metabolic effects have a balanced state, which results in the same administration dose, due to the equilibrium of FPGS and GGH, fast infusion (high blood concentration) and slow infusion (low blood concentration) The net growth rate of intracellular MTXPGS in the environment is not large. Therefore, when the slow infusion, the ...

AI Technical Summary

Problems solved by technology

However, the current analysis of FPGS and GGH mainly stays at the level of enzyme activity measurement. This method is complicated, time-consuming, and the reproducibility of the results is poor, resulting in weak comparability of analysis results between different batches and laboratories. cannot be widely used

Some research reports have shown that the enzymatic activity of FPGS and GGH is directly proportional to their expression. Although some researchers have studied and analyzed the expression of the two, the analysis methods mainly include reverse transcription-polymerase chain reaction (Reverse Transcription-Polymerase Chain Reaction). Polymerase ChainReaction, RT-PCR) and Western Blot (Western Blot), wherein, RT-PCR is analyzed from the mRNA level, due to the influence of many factors, such as post-transcriptional modification, the half-life of protein and mRNA is different, etc., mRNA level and The translation levels are not equivalent, and the protein is the final form of physiological functions, so RT-PCR cannot achieve accurate analysis; and although Western Blot analyzes from the level of protein expression, its sensitivity is low, and it cannot analyze the intercellular FPGS and Distinguishing the slight difference in GGH expression level cannot guide clinical medication at all; secondly, FPGS and GGH are endogenous proteins, which have a certain sequence homology with other endogenous proteins, and may be accompanied by certain antigen-antibody crossover. reaction, leading to errors in quantitative results

Therefore, this detection method can only be used for qualitative or semi-quantitative research and the reproducibility of the results is low. At present, it has not been realized in clinical practice to quantitatively monitor FPGS and GGH to provide help for clinical guidance.

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