Mass spectral analysis of the apolipoproteins on mouse high density lipoproteins. Detection of post-translational modifications.

摘要: Using mass spectrometry, we have recently reported on molecular masses of the apolipoproteins associated with porcine and equine HDL. In addition to obtaining accurate for various apolipoproteins, also were able detect variations due post-translational modifications. present study, used these same approaches characterize in two inbred mouse strains, C57BL/6 BALB/c. Comparing our data calculated values weight, identify correct sequences several major apolipoproteins. Analyses carried out ultracentrifugally isolated Prior analyses by electrospray ionization spectrometry (ESI-MS), separated either size exclusion or reverse phase chromatography. The apoA-I, proapoA-I, apoA-II, proapoA-II, apoC-I apoC-III obtained. obtained differences apoA-II observed. this post-translationally modified involving loss amino acids from both N- C-termini, oxidation methionine residues possible acylation, noted following reverse-phase separation. Further tandem (MSMS) done tryptic digests chromatography enabled us confirm sequence between verify selected apoA-I that had been entered into GenBank which methionines apoE converted sulfoxides.