Identification and characterization of novel reptile cathelicidins from elapid snakes.
Three cDNA sequences coding for elapid cathelicidins were cloned from constructed venom gland cDNA libraries of Naja atra, Bungarus fasciatus and Ophiophagus hannah. The open reading frames of the cloned elapid cathelicidins were all composed of 576bp and coded for 191 amino acid residue protein precursors. Each of the deduced elapid cathelicidin has a 22 amino acid residue signal peptide, a conserved cathelin domain of 135 amino acid residues and a mature antimicrobial peptide of 34 amino acid residues. Unlike the highly divergent cathelicidins in mammals, the nucleotide and deduced protein sequences of the three cloned elapid cathelicidins were remarkably conserved. All the elapid mature cathelicidins were predicted to be cleaved at Valine157 by elastase. OH-CATH, the deduced mature cathelicidin from king cobra, was chemically synthesized and it showed strong antibacterial activity against various bacteria with minimal inhibitory concentration of 1-20microg/ml in the presence of 1% NaCl. Meanwhile, the synthetic peptide showed no haemolytic activity toward human red blood cells even at a high dose of 200microg/ml. Phylogenetic analysis of cathelicidins from vertebrate suggested that elapid and viperid cathelicidins were grouped together in the tree. Snake cathelicidins were evolutionary closely related to the neutrophilic granule proteins (NGPs) from mouse, rat and rabbit. Snake cathelicidins also showed a close relationship with avian fowlicidins (1-3) and chicken myeloid antimicrobial peptide 27. Elapid cathelicidins might be used as models for the development of novel therapeutic drugs.
Zhao
Hui
H
Kunming Institute of Zoology, The Chinese Academy of Sciences, Kunming, Yunnan 650223, China.
Gan
Tong-Xiang
TX
Liu
Xiao-Dong
XD
Jin
Yang
Y
Lee
Wen-Hui
WH
Shen
Ji-Hong
JH
Zhang
Yun
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D054804:Cathelicidins / Q000145:classification / Q000235:genetics* / Q000378:metabolism* / Q000494:pharmacology; D003001:Cloning, Molecular; D004546:Elapid Venoms / Q000737:chemistry*; D017815:Elapidae; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D051379:Mice; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010455:Peptides / Q000145:classification / Q000235:genetics* / Q000378:metabolism* / Q000494:pharmacology; D010802:Phylogeny; D011817:Rabbits; D051381:Rats; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein
D054804:Cathelicidins; D004546:Elapid Venoms; D010455:Peptides