title: A novel metalloprotease from Vipera lebetina venom induces human endothelial cell apoptosis.
abstract: A novel endothelial cell apoptosis inducing metalloprotease (VLAIP) was found in the snake venom of Vipera lebetina. This metalloprotease is a heterodimeric glycoprotein with molecular mass of about 106 kDa. The protease hydrolyzes azocasein, fibrinogen and oxidized insulin B-chain. The enzyme readily hydrolyzes the Aalpha-chain and more slowly Bbeta-chain of fibrinogen. VLAIP does not cleave fibrin. The complete amino acid sequences of the two different monomers of VLAIP are deduced from the nucleotide sequences of cDNAs encoding these proteins. The full-length cDNA sequences of the VLAIP-A and VLAIP-B encode open reading frames of 616 and 614 amino acids that include signal peptide, propeptide and mature metalloproteinase with disintegrin-like and cysteine-rich domains. VLAIP belongs to the metalloprotease/disintegrin family of reprolysins and has high identity with the proteins that induce apoptosis of endothelial cells. Treatment of HUVEC cells with VLAIP induces changes in the attachment of cells to the substrate and causes cell death. We demonstrated that VLAIP inhibits endothelial cell adhesion to extracellular matrix proteins: fibrinogen, fibronectin, vitronectin, collagen I, and collagen IV. The induction of apoptosis by VLAIP was shown by means of a typical DNA fragmentation pattern of apoptotic cells as well as by monitoring phosphatidylserine externalization using annexin V-FITC staining and flow cytometric analysis.
authors.affiliation: National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia.
authors.forename: Katrin
authors.initials: K
authors.lastname: Trummal
authors.forename: Külli
authors.initials: K
authors.lastname: Tõnismägi
authors.forename: Ene
authors.initials: E
authors.lastname: Siigur
authors.forename: Anu
authors.initials: A
authors.lastname: Aaspõllu
authors.forename: Annika
authors.initials: A
authors.lastname: Lopp
authors.forename: Tarvo
authors.initials: T
authors.lastname: Sillat
authors.forename: Riste
authors.initials: R
authors.lastname: Saat
authors.forename: Lagle
authors.initials: L
authors.lastname: Kasak
authors.forename: Indrek
authors.initials: I
authors.lastname: Tammiste
authors.forename: Priit
authors.initials: P
authors.lastname: Kogerman
authors.forename: Nisse
authors.initials: N
authors.lastname: Kalkkinen
authors.forename: Jüri
authors.initials: J
authors.lastname: Siigur
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001483:Base Sequence; D002448:Cell Adhesion / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects* / Q000502:physiology; D016326:Extracellular Matrix Proteins / Q000502:physiology; D006801:Humans; D045726:Metalloproteases / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014757:Viper Venoms / Q000201:enzymology / Q000494:pharmacology*
chemical_list: D016326:Extracellular Matrix Proteins; D014757:Viper Venoms; D045726:Metalloproteases