title: Matrix metalloproteinase homologues from Arabidopsis thaliana. Expression and activity.
abstract: Five genes potentially encoding novel matrix metalloproteinases (MMPs) have been identified on the Arabidopsis thaliana data base. The predicted proteins have a similar domain structure to mammalian MMP-7, with a propeptide and catalytic domain but no C-terminal hemopexin-like domain. Four of the A. thaliana MMPs (At-MMPs) have a predicted C-terminal transmembrane domain. The At-MMPs are differentially expressed in flower, leaf, root, and stem tissues from 14-day-old plants. The cDNA for one of the At-MMPs (At1-MMP) was cloned and expressed in Escherichia coli. Following refolding and purification, the proenzyme At1-MMP was shown to undergo autolytic activation in the presence of an organomercurial with a concomitant decrease in M(r). In contrast to this, trypsin-treatment led to the formation of an inactive product. The activated At1-MMP digested myelin basic protein, but was unable to digest gelatin or casein. Three peptide substrates for MMPs were also cleaved by At1-MMP. The enzyme activity of At1-MMP was inhibited by human tissue inhibitors of metalloproteinases 1 and 2 and the hydroxamate inhibitor BB-94.
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom.
authors.forename: J M
authors.initials: JM
authors.lastname: Maidment
authors.forename: D
authors.initials: D
authors.lastname: Moore
authors.forename: G P
authors.initials: GP
authors.lastname: Murphy
authors.forename: G
authors.initials: G
authors.lastname: Murphy
authors.forename: I M
authors.initials: IM
authors.lastname: Clark
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology*; D001483:Base Sequence; D016208:Databases, Factual; D004591:Electrophoresis, Polyacrylamide Gel; D015870:Gene Expression; D006801:Humans; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D020782:Matrix Metalloproteinases / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D004676:Myelin Basic Protein / Q000378:metabolism; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013876:Thiophenes / Q000494:pharmacology; D019714:Tissue Inhibitor of Metalloproteinases / Q000378:metabolism
chemical_list: D061965:Matrix Metalloproteinase Inhibitors; D004676:Myelin Basic Protein; D013876:Thiophenes; D019714:Tissue Inhibitor of Metalloproteinases; D010649:Phenylalanine; C080985:batimastat; D020782:Matrix Metalloproteinases; D019278:Matrix Metalloproteinase 3