Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2007359 | Peptides | 2008 | 8 Pages |
Abstract
Snake venom Kunitz/BPTI members are good tools for understanding of structure-functional relationship between serine proteases and their inhibitors. A novel dual Kunitz/BPTI serine proteinase inhibitor named OH-TCI (trypsin- and chymotrypsin-dual inhibitor from Ophiophagus hannah) was isolated from king cobra venom by three chromatographic steps of gel filtration, trypsin affinity and reverse phase HPLC. OH-TCI is composed of 58 amino acid residues with a molecular mass of 6339 Da. Successful expression of OH-TCI was performed as the maltose-binding fusion protein in E. coli DH5α. Much different from Oh11-1, the purified native and recombinant OH-TCI both had strong inhibitory activities against trypsin and chymotrypsin although the sequence identity (74.1%) between them is very high. The inhibitor constants (Ki) of recombinant OH-TCI were 3.91 Ã 10â7 and 8.46 Ã 10â8 M for trypsin and chymotrypsin, respectively. To our knowledge, it was the first report of Kunitz/BPTI serine proteinase inhibitor from snake venom that had equivalent trypsin and chymotrypsin inhibitory activities.
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Authors
Ying-Ying He, Shu-Bai Liu, Wen-Hui Lee, Jin-Qiao Qian, Yun Zhang,