title: The natriuretic peptide/helokinestatin precursor from Mexican beaded lizard (Heloderma horridum) venom: Amino acid sequence deduced from cloned cDNA and identification of two novel encoded helokinestatins.
abstract: Natriuretic peptides are common components of reptile venoms and molecular cloning of their biosynthetic precursors has revealed that in snakes, they co-encode bradykinin-potentiating peptides and in venomous lizards, some co-encode bradykinin inhibitory peptides such as the helokinestatins. The common natriuretic peptide/helokinestatin precursor of the Gila Monster, Heloderma suspectum, encodes five helokinestatins of differing primary structures. Here we report the molecular cloning of a natriuretic peptide/helokinestatin precursor cDNA from a venom-derived cDNA library of the Mexican beaded lizard (Heloderma horridum). Deduction of the primary structure of the encoded precursor protein from this cloned cDNA template revealed that it consisted of 196 amino acid residues encoding a single natriuretic peptide and five helokinestatins. While the natriuretic peptide was of identical primary structure to its Gila Monster (H. suspectum) homolog, the encoded helokinestatins were not, with this region of the common precursor displaying some significant differences to its H. suspectum homolog. The helokinestatin-encoding region contained a single copy of helokinestatin-1, 2 copies of helokinestatin-3 and single copies of 2 novel peptides, (Phe)(5)-helokinestatin-2 (VPPAFVPLVPR) and helokinestatin-6 (GPPFNPPPFVDYEPR). All predicted peptides were found in reverse phase HPLC fractions of the same venom. Synthetic replicates of both novel helokinestatins were found to antagonize the relaxing effect of bradykinin on rat tail artery smooth muscle. Thus lizard venom continues to provide a source of novel biologically active peptides.
authors: Molecular Therapeutics Research, School of Pharmacy, Queen's University, Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK.
authors: Chengbang
authors: C
authors: Ma
authors: Mu
authors: M
authors: Yang
authors: Mei
authors: M
authors: Zhou
authors: Yuxin
authors: Y
authors: Wu
authors: Lei
authors: L
authors: Wang
authors: Tianbao
authors: T
authors: Chen
authors: Anwei
authors: A
authors: Ding
authors: Chris
authors: C
authors: Shaw
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001158:Arteries / Q000187:drug effects; D001920:Bradykinin / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D056148:Chromatography, Reverse-Phase; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D015723:Gene Library; D008116:Lizards / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008800:Mexico; D008969:Molecular Sequence Data; D009126:Muscle Relaxation / Q000187:drug effects; D045265:Natriuretic Peptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D011498:Protein Precursors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D046509:Tissue Culture Techniques; D014688:Venoms / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology
chemical_list: D018076:DNA, Complementary; D045265:Natriuretic Peptides; D011498:Protein Precursors; D014688:Venoms; C527846:helokinestatin; D001920:Bradykinin