cDNA cloning and some additional peptide characterization of a single-chain vascular apoptosis-inducing protein, VAP2.
Vascular apoptosis-inducing proteins (VAPs) from hemorrhagic snake venom are apoptosis-inducing toxins targeting vascular endothelial cells. Well-characterized VAPs consist of disulfide-bridged double chains (ddVAPs). The authors previously described a single-chain VAP (scVAP), VAP2 from Crotalus atrox, which also induces apoptosis in endothelial cells (Masuda et al., 1998, European Journal of Biochemistry, 253, 36-41). The authors report here the whole cDNA sequences and some additional peptide characteristics of VAP2. In addition to the apoptosis-inducing activity of VAP2, the toxin displays a cell-detaching activity after incubation in high-salt conditions. These observations indicate that the apoptosis and cell-detaching functions can be discriminated. Analysis of the cell-detaching activity also revealed that VAP2 consists of two similar peptides, VAP2A and VAP2B, which are members of the PIII-type snake venom metalloproteases (SVMPs). The VAP2A cDNA encodes a 609-amino acid protein. In contrast, the peptide sequences of VAP2B were identical to that of catrocollastatin, an inhibitor of platelet aggregation. VAP2A and VAP2B interact with each other to form a noncovalent dimer similar to the ddVAPs, which was detected by native polyacrylamide gel electrophoresis. These data show some new characteristics of VAPs, which are important to clarify the apoptotic pathways in vascular endothelial cells.
Masuda
Shinako
S
Marine Biological Laboratory, Graduate School of Science, Nagoya University, Toba, Mie 517-004, Japan.
Maeda
Hiroki
H
Miao
Jun Ying
JY
Hayashi
Hiroshi
H
Araki
Satohiko
S
D000595:Amino Acid Sequence; D001483:Base Sequence; D002478:Cells, Cultured; D003001:Cloning, Molecular; D003435:Crotalid Venoms / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D018076:DNA, Complementary / Q000235:genetics*; D019281:Dimerization; D006801:Humans; D008666:Metalloendopeptidases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism*; D020539:Sequence Analysis, Protein
D003435:Crotalid Venoms; D018076:DNA, Complementary; D010455:Peptides; D008666:Metalloendopeptidases; C512262:VAP2 protein, Crotalus atrox