Molecular characterization of L-amino acid oxidase from king cobra venom.
An L-amino acid oxidase from Ophiophagus hannah snake venom (Oh-LAAO) was purified by successive gel filtration, ion-exchange and heparin chromatography. Oh-LAAO did not induce platelet aggregation; however, it had potent inhibitory activity on platelet aggregation induced by ADP and U46619, but showed no effect on platelet aggregation induced by thrombin, mucetin, ristocetin and stejnulxin. By RT-PCR and 5'-RACE methods, the complete Oh-LAAO cDNA was cloned from the venom gland total RNA preparations. The cDNA sequence contains an open-reading frame (ORF) of 1476-bp, which encodes a protein of 491 amino acids comprising a signal peptide of 25 amino acids and 466-residue mature protein. The predicted protein sequence of Oh-LAAO was confirmed by N-terminal and trypsin-digested internal peptides sequencing together with peptide mass fingerprinting. cDNAs encoding for ORF of LAAOs from Bungarus fasciatus and B. multicinctus were cloned and reported in this study. In addition, partial cDNA encoding for Naja atra LAAO was also reported. Oh-LAAO shared approximately 50% protein sequence identity with other known snake venom LAAOs. Phylogenetic analysis indicated that Oh-LAAO is evolutionary distant to other snake venom LAAOs.
Jin
Yang
Y
Biotoxin Units, Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China.
Lee
Wen-Hui
WH
Zeng
Lin
L
Zhang
Yun
Y
D000595:Amino Acid Sequence; D001483:Base Sequence; D004546:Elapid Venoms / Q000201:enzymology*; D006801:Humans; D050830:L-Amino Acid Oxidase / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000494:pharmacology; D008969:Molecular Sequence Data; D010802:Phylogeny; D010974:Platelet Aggregation / Q000187:drug effects
D004546:Elapid Venoms; D050830:L-Amino Acid Oxidase