Tandem mass spectrometry of heparan sulfate negative ions: sulfate loss patterns and chemical modification methods for improvement of product ion profiles.

ABSTRACT: Heparan sulfate (HS) is a polysaccharide modified with sulfation, acetylation, and epimerization that enable its binding with protein ligands and regulation of important biological processes. Tandem mass spectrometry has been employed to sequence linear biomolecules e.g., proteins and peptides. However, its application in structural characterization of HS is limited due to the neutral loss of sulfate (SO(3)) during collisional induced dissociation (CID). In this report, we studied the dissociation patterns of HS disaccharides and demonstrate that the N-sulfate (N-S) bond is especially facile during CID. We identified factors that influence the propensities of such losses from precursor ions and proposed a Free Proton Index (FPI) to help select ions that are able to produce meaningful backb

SUBMITTER: Shi X 

PROVIDER: S-EPMC4146577 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature