title: Analysis of apolipoprotein A-I as a substrate for matrix metalloproteinase-14.
abstract: Substrates for matrix metalloproteinase (MMP)-14 were previously identified in human plasma using proteomic techniques. One putative MMP-14 substrate was apolipoprotein A-I (apoA-I), a major component of high-density lipoprotein (HDL). In vitro cleavage assays showed that lipid-free apoA-I is a more accessible substrate for MMP-14 compared to lipid-bound apoA-I, and that MMP-14 is more prone to digest apoA-I than MMP-3. The 28-kDa apoA-I was cleaved into smaller fragments of 27, 26, 25, 22, and 14-kDa by MMP-14. ApoA-I sites cleaved by MMP-14 were determined by isotope labeling of C-termini derived from the cleavage and analysis of the labeled peptides by mass spectrometry, along with N-terminal sequencing of the fragments. Cleavage of apoA-I by MMP-14 resulted in a loss of ability to form HDL. Our results suggest that cleavage of lipid-free apoA-I by MMP-14 may contribute to reduced HDL formation, and this may be occurring during the development of various vascular diseases as lipid metabolism is disrupted.
authors.affiliation: Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea.
authors.forename: Jun Hyoung
authors.initials: JH
authors.lastname: Park
authors.forename: Sung-Min
authors.initials: SM
authors.lastname: Park
authors.forename: Ki-Hoon
authors.initials: KH
authors.lastname: Park
authors.forename: Kyung-Hyun
authors.initials: KH
authors.lastname: Cho
authors.forename: Seung-Taek
authors.initials: ST
authors.lastname: Lee
mesh_terms: D016632:Apolipoprotein A-I / Q000097:blood / Q000737:chemistry*; D001798:Blood Proteins / Q000737:chemistry; D006801:Humans; D053511:Matrix Metalloproteinase 14 / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity
chemical_list: D016632:Apolipoprotein A-I; D001798:Blood Proteins; C507086:MMP14 protein, human; D053511:Matrix Metalloproteinase 14