title: Precursors of three unique cysteine-rich peptides from the scorpion Buthus martensii Karsch.
abstract: Scorpion venoms contain a large number of small peptides with diverse primary structures and unique pharmacological functions. From a cDNA library prepared from venom glands of the Chinese scorpion Buthus martensii Karsch, clones encoding precursors of three unique cysteine-rich peptides named BmTXKS3, BmTXLP2 and BmAP1 have been isolated and sequenced. These precursors are composed of 54, 94 and 89 amino acids, respectively, containing a signal peptide in their N-termini. Sequence analysis shows that BmTXKS3 and BmTXLP2 are two novel members of a scorpion toxin family sharing cysteine-stabilized alpha-helical folds. BmAP1 possesses a distinctive cystine framework, which is similar to some serine protease inhibitors and the segments of several extracellular proteins.
authors.affiliation: Department of Biotechnology, College of Life Sciences, Wuhan University, Wuhan 430072, Hubei Province, PR China. shunyizhu@hotmail.com
authors.forename: Shunyi
authors.initials: S
authors.lastname: Zhu
authors.forename: Wenxin
authors.initials: W
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D003545:Cysteine / Q000737:chemistry*; D018076:DNA, Complementary / Q000378:metabolism; D015723:Gene Library; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012604:Scorpion Venoms / Q000737:chemistry*; D012605:Scorpions / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015842:Serine Proteinase Inhibitors / Q000737:chemistry; D012984:Software
chemical_list: C464452:AP1 protein, Buthus martensii; D018076:DNA, Complementary; D010455:Peptides; D012604:Scorpion Venoms; D015842:Serine Proteinase Inhibitors; C464450:TXKS3 protein, Buthus martensii; C464451:TXLP2 protein, Buthus martensii; D003545:Cysteine