Mapping of macrophage elastase cleavage sites in insoluble human skin elastin.
Macrophage elastase (MMP-12) is a member of the family of matrix metalloproteinases (MMPs) and is active against multiple extracellular protein substrates such as elastin. Its effect on elastin is central to emphysema in the lung and photoaging of skin. Its expression in the skin increases on photodamaged skin and upon aging. Detecting and characterizing peptides cleaved in elastin, therefore, helps to understand such degradative disease processes in the skin and is also needed to assist in the rational design of agents that specifically inhibit the degradation. In this study, cleavage sites of MMP-12 in human skin elastin were extensively investigated. The peptides formed as a result of cleavages by this enzyme in the human skin elastin were characterized using mass spectrometry. A total of 41 peptides ranging from 4 to 41 amino acids were identified and 36 cleavage sites were determined. Amino acids encoded by exons 5, 6, 26, 28-31 were particularly susceptible to cleavages by MMP-12 and none or very few cleavages were detected from domains encoded by the remaining exons. The amino acid preferences of the different subsites on the catalytic domain of MMP-12 were analyzed.
Taddese
Samuel
S
Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
Weiss
Anthony S
AS
Neubert
Reinhard H H
RH
Schmelzer
Christian E H
CE
D000595:Amino Acid Sequence; D020134:Catalytic Domain / Q000235:genetics; D004549:Elastin / Q000737:chemistry / Q000378:metabolism*; D005091:Exons / Q000235:genetics; D006801:Humans; D053508:Matrix Metalloproteinase 12 / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry; D011994:Recombinant Proteins / Q000378:metabolism; D012867:Skin / Q000737:chemistry*; D012995:Solubility; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D014333:Tropoelastin / Q000737:chemistry / Q000378:metabolism
D010446:Peptide Fragments; D011994:Recombinant Proteins; D014333:Tropoelastin; D004549:Elastin; C507122:MMP12 protein, human; D053508:Matrix Metalloproteinase 12