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Antibody-Free Approach for the Global Analysis of Protein Methylation
journal contribution
posted on 2016-11-01, 00:00 authored by Keyun Wang, Mingming Dong, Jiawei Mao, Yan Wang, Yan Jin, Mingliang Ye, Hanfa ZouProtein methylation
is receiving more and more attention for its
important regulating role in diverse biological processes including
epigenetic regulation of gene transcription, RNA processing, DNA damage
repair, and signal transduction. Global analysis of protein methylation
at the proteome level requires the enrichment of methylated peptides
with various forms; unfortunately, the immunoaffinity purification
method can only enrich a subset of them due to lacking of pan specific
antibody. Because methylation does not significantly alter the physicochemical
properties of arginine or lysine residues, chemical approach for global
methylome analysis is still at infancy. In this study, by exploiting
the fact that the methylation on Arg and Lys prohibiting the cleavage
by proteases for these sites, we developed an antibody-free method
to enrich methylated peptides, which enabled the identification of
887 methylation forms on 768 sites from HepG2 cells. This technique
allows the simultaneous analysis of both Lys and Arg methylation while
it has better performance for the identification of Arg methylation.
It should find broad applications in studying methylation regulated
biological processes.