A method for identifying protein methylation

Abstract

The invention relates to a new protein methylation identification method. According to the present invention, the methylation site is labeled by using the novel heavy isotope labeled methionine, and the methylation peptide fragment analysis method integrating the methionine cell culture amino acid stable isotope labeling, the identification and extraction of the fragmentation spectrum of the methylation peptide fragment, and the spectrum peak demethylation treatment is developed, and is used in the large-scale analysis of methylated proteome; the amino acid labeling method can distinguish themethylated peptide fragment from the peptide fragment containing methionine, can identify and extract the fragmentation spectrum derived from the methylated peptide fragment, and can demethylate the fragmentation spectrum so as to obtain the spectrum of the unmethylated peptide fragment, and the peptide fragment sequence is determined by searching in a database so as to determine the modificationsite by binding to the spectrum of the methylated peptide fragment; and the method does not require the preset of the modification type so as to simultaneously analyze all the known methylation types.

Description

technical field [0001] The invention belongs to the technical field of methylated proteomics in the direction of proteomics research, and specifically relates to a new identification method of methylated proteomics. Background technique [0002] Protein methylation is catalyzed by S-adenosylmethionine (SAM)-dependent methyltransferases, and is one of the most common post-translational modifications of proteins. Methylation modification plays an important regulatory role in the regulation of many physiological processes. Studies have shown that protein methylation can regulate the intramolecular or intermolecular interactions of target proteins; affect their affinity with RNA, thereby affecting a variety of cellular processes, including transcription regulation, cellular localization, ribosome assembly, and RNA processing , maturation of heterogeneous ribosomal ribosomal proteins (hnRNPs), protein-protein interactions, accuracy of translation, nuclear transport, protein and ...

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Problems solved by technology

But in the traditional labeling method (document 1: S.-E.Ong, G.Mittler, M.Mann, Identifying and quantifying in vivo methylation sites by heavy methyl SILAC, Nat Methods 1 (2004) 119-126), for containing The difference in molecular weight introduced by isotope labeling is the same for peptides containing methionine and peptides containing methylation modifications, so the two types of peptides cannot be distinguished

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