system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Apolipoprotein A-I, Blood Chemical Analysis, Chromatography, Liquid, Glycated Hemoglobin A, Glycosylation, Humans, Mass Spectrometry, Oxidation-Reduction, Proteome, Sequence Deletion, Time Factors.
user
Does a fast semi-quantitative LC-MS method for measurement of intact apolipoprotein A-I reveal novel proteoforms in serum? Context: Surrogate markers for reverse cholesterol transport (RCT) efficiency such as HDL cholesterol and immune methods for apolipoprotein A-I (ApoA-I) may not fully reflect the actual efficiency of the RCT pathway. Several genetic variants and different posttranslational proteoforms of ApoA-I may unevenly affect the functionality of the HDL particle to efflux cholesterol. A method employing top-down immunoaffinity LC-MS of ApoA-I in order to characterize the most prevalent ApoA-I proteoforms in human plasma is described. Diluted plasma was directly injected into a 2D LC-MS system consisting of an affinity column and an analytical column. Enriched ApoA-I fractions were introduced into the MS and intact or fragmented ApoA-I was analyzed. ApoA-I as detected by the described LC-MS method distributes into at least 14 major potential proteoforms exceeding detection limit in human plasma. Substantial amounts of ApoA-I in plasma were found to occur as truncated, oxidized, glycated and glycosylated proteoforms. Levels of glycated ApoA-I distinguished significantly diabetic from non-diabetic samples. In addition novel truncated and glycosylated proteoforms were detected.
assistant
ApoA-I proteoforms measured by LC-MS represent a useful approach to augment the clinical picture of ApoA-I and its function in health and disease. Final Decision: yes