Quantifying homologous proteins and proteoforms

ABSTRACT: Many proteoforms - arising from alternative splicing, post-translational modifications (PTMs), or paralogous genes - have distinct biological functions, such as histone PTM proteoforms. However, their quantification by existing bottom-up mass-spectrometry (MS) methods is undermined by peptide-specific biases. To avoid these biases, we developed and implemented a first-principles model (HIquant) for quantifying proteoform stoichiometries. We characterized when MS data allow inferring proteoform stoichiometries by HIquant, derived an algorithm for optimal inference, and demonstrated experimentally high accuracy in quantifying fractional PTM occupancy without using external standards, even in the challenging case of the histone modification code. HIquant server is implemented at: https://web.northeastern.edu/slavov/2014_HIquant/

INSTRUMENT(S): LTQ Orbitrap Elite, Q Exactive

ORGANISM(S): Saccharomycetales (ncbitaxon:4892) Homo Sapiens (ncbitaxon:9606)

SUBMITTER: Nikolai Slavov  

PROVIDER: MSV000081857 | MassIVE | Fri Dec 22 11:49:00 GMT 2017

SECONDARY ACCESSION(S): PXD008557

REPOSITORIES: MassIVE