Trypsin Partially Cleaves Apolipoprotein A-I (ApoA-I) Precursor into Mature ApoA-I Hindering the Quantification of Naturally Occurring ApoA-I Proteoforms by Liquid Chromatography in Multiple Reaction Monitoring Mode Mass Spectrometry (LC-MRM-MS).

ABSTRACT: Apolipoprotein A-I (ApoA-I), one of the most abundant proteins in plasma and the major protein component of high-density lipoprotein (HDL), is naturally found in several proteoforms; two of them are ProApoA-I and mature ApoA-I. These two proteoforms of ApoA-I coexist in biological samples and differ only in their N-terminal end. Virtually, the only way to differentiate them is by detecting the proteoform-specific N-terminal proteolytic peptides (RHFWQQDEPPQSPWDR and DEPPQSPWDR, respectively) using liquid chromatography in multiple reaction monitoring mode mass spectrometry (LC-MRM-MS). We have developed a bottom-up LC-MRM-MS method to simultaneously detect proApoA-I and mature ApoA-I. To test the specificity of the method, we digested with trypsin purified mature ApoA-I and recombinant pro

SUBMITTER: Llorens-Cebria C 

PROVIDER: S-EPMC11450815 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature