A direct, ratiometric, and quantitative MALDI-MS assay for protein methyltransferases and acetyltransferases.

ABSTRACT: Protein methylation and acetylation play important roles in biological processes, and misregulation of these modifications is involved in various diseases. Therefore, it is critical to understand the activities of the enzymes responsible for these modifications. Herein we describe a sensitive method for ratiometric quantification of methylated and acetylated peptides via MALDI-MS by direct spotting of enzymatic methylation and acetylation reaction mixtures without tedious purification procedures. The quantifiable detection limit for peptides with our method is approximately 10 fmol. This is achieved by increasing the signal-to-noise ratio through the addition of NH4H2PO4 to the matrix solution and reduction of the matrix α-cyanohydroxycinnamic acid concentration to 2 mg/ml. We have demonst

SUBMITTER: Richardson SL 

PROVIDER: S-EPMC4855292 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature