title: Purification and cloning of a novel C-type lectin-like protein with platelet aggregation activity from Trimeresurus mucrosquamatus venom.
abstract: TMVA, a novel C-type lectin-like protein that induces platelet aggregation in a dose-dependent manner, was purified from the venom of Trimeresurus mucrosquamatus. It consists of two subunits, alpha (15536 Da) and beta (14873 Da). The mature amino acid sequences of the alpha (135 amino acids) and beta subunits (123 amino acids) were deduced from cloned cDNAs. Both of the sequences show great similarity to C-type lectin-like venom proteins, including a carbohydrate recognition domain. The cysteine residues of TMVA are conserved at positions corresponding to those of flavocetin-A and convulxin, including the additional Cys135 in the alpha subunit and Cys3 in the beta subunit. SDS-PAGE, mass spectrometry analysis and amino acid sequence showed that native TMVA exists as two convertible multimers of (alpha beta)(2) and (alpha beta)(4) with molecular weights of 63680 and 128518 Da, respectively. The (alpha beta)(2) complex is stabilized by an interchain disulfide bridge between the two alpha beta-heterodimers, whereas the stabilization of the (alpha beta)(4) complex seems to involve non-covalent interactions between the (alpha beta)(2) complexes.
authors.affiliation: Department of Animal Toxicology, Kunming Institute of Zoology, Chinese Academy of Sciences, 650223, Yunnan, Kunming, People's Republic of China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
authors.forename: Qiu-Min
authors.initials: QM
authors.lastname: Lu
authors.forename: Yang
authors.initials: Y
authors.lastname: Jin
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.forename: Ji-Fu
authors.initials: JF
authors.lastname: Wei
authors.forename: Wan-Yu
authors.initials: WY
authors.lastname: Wang
authors.forename: Yu-Liang
authors.initials: YL
authors.lastname: Xiong
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001792:Blood Platelets / Q000187:drug effects; D003001:Cloning, Molecular; D003435:Crotalid Venoms / Q000737:chemistry* / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D037181:Lectins, C-Type / Q000235:genetics* / Q000302:isolation & purification*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010974:Platelet Aggregation; D020539:Sequence Analysis, Protein; D017841:Trimeresurus; D014757:Viper Venoms / Q000235:genetics* / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D003435:Crotalid Venoms; D018076:DNA, Complementary; D037181:Lectins, C-Type; C468283:TMVA protein, Trimeresurus mucrosquamatus; C029748:Trimeresurus venoms; D014757:Viper Venoms