Flexible xxx-asp/asn and gly-xxx residues of equine cytochrome C in matrix-assisted laser desorption/ionization in-source decay mass spectrometry.

ABSTRACT: The backbone flexibility of a protein has been studied from the standpoint of the susceptibility of amino acid residues to in-source decay (ISD) in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). Residues more susceptible to MALDI-ISD, namely Xxx-Asp/Asn and Gly-Xxx, were identified from the discontinuous intense peak of c'-ions originating from specific cleavage at N-Cα bonds of the backbone of equine cytochrome c. The identity of the residues susceptible to ISD was consistent with the known flexible backbone amides as estimated by hydrogen/deuterium exchange (HDX) experiments. The identity of these flexible amino acid residues (Asp, Asn, and Gly) is consistent with the fact that these residues are preferred in flexible secondary structure free from intramolecula

SUBMITTER: Takayama M 

PROVIDER: S-EPMC3775822 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature