Crystal structure of the platelet activator convulxin, a disulfide-linked alpha4beta4 cyclic tetramer from the venom of Crotalus durissus terrificus

• Published in: Biochemical and biophysical research communications Vol. 310; no. 2; pp. 478 - 482
• Main Authors: Murakami, M T, Zela, S P, Gava, L M, Michelan-Duarte, S, Cintra, A C O, Arni, R K
• Format: Journal Article
• Language: English
• Published: United States 17.10.2003
• Subjects: Amino Acid Sequence; Animals; Binding Sites; Calcium - metabolism; Crotalid Venoms - chemistry; Crotalid Venoms - metabolism; Crotalus; Crystallography, X-Ray; Disulfides - chemistry; Lectins, C-Type - chemistry; Lectins, C-Type - metabolism; Models, Molecular; Molecular Sequence Data; Protein Structure, Quaternary; Protein Subunits; Sequence Alignment
• ISSN: 0006-291X

Convulxin (CVX), a C-type lectin, isolated from the venom of the South American rattlesnake Crotalus durissus terrificus, causes cardiovascular and respiratory disturbances and is a potent platelet activator which binds to platelet glycoprotein GPVI. The structure of CVX has been solved at 2.4A resolution to a crystallographic residual of 18.6% (R(free)=26.4%). CVX is a disulfide linked heterodimer consisting of homologous alpha and beta chains. The heterodimers are additionally linked by disulfide bridges to form cyclic alpha(4)beta(4)heterotetramers. These domains exhibit significant homology to the carbohydrate-binding domains of C-type lectins, to the factor IX-binding protein (IX-bp), and to flavocetin-A (Fl-A) but sequence and structural differences are observed in both the domains in the putative Ca(2+)and carbohydrate binding regions.