Two serine protease inhibitors from the skin secretions of the toad, Bombina microdeladigitora.
Two serine protease inhibitors (named BMSI 1 and BMSI 2, respectively) were identified from the skin secretions of the toad, Bombina microdeladigitora. The cDNAs encoding BMSIs were cloned from a cDNA library prepared from the toad skin. The deduced complete amino acid sequences of BMSIs indicate that mature BMSI 1 and BMSI 2 are composed of 60 amino acids including 10 half-cystines to form 5 disulfide bridges. A FASTA search in the databanks revealed that BMSIs exhibit sequence similarity with other serine protease inhibitors from amphibians of the genus Bombina. BMSI 1 potently inhibited trypsin and thrombin with a K(i) value of 0.02 microM and 0.15 microM, respectively. Sequence analysis revealed that all serine protease inhibitors from five amphibians of the genus Bombina share highly conserved primary structures.
Lu
Xiangyun
X
Biotoxin Units of Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China.
Ma
Yufang
Y
Wu
Jing
J
Lai
Ren
R
D000595:Amino Acid Sequence; D000818:Animals; D001001:Anura / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D006868:Hydrolysis; D008297:Male; D008969:Molecular Sequence Data; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012867:Skin / Q000378:metabolism*
D018076:DNA, Complementary; D015842:Serine Proteinase Inhibitors