- 作者: 陳水田 ; 楊茂雄 ; 吳松陽 等
- 作者服務機構: 中央研究院生物化學研究所
- 中文摘要: Using the crystal structure of cobra venom cardiotoxin as a templet, a computer designed peptide with a novel conformation and biological activity has been synthesized chemically. The designed peptide utilized two calcium coordination sites instead of disulfide bridges to hold the conformation. The coordination sites were introduced at the cleft of three .beta.-sheet strands by replacing the residues of Leu-1, Leu-26, Ser-28, Leu-48, and Ser-55 with Glu and using their .gamma.-carboxyl groups as legends. The residues of Cys at positions 3, 14, 21, 38, 42, 53, 54 and 59 of the four disulfide bridges were changed with Gly to remove all the disulfide bonds. Circular dichroism spectra showed that the synthesized peptide has a conformation similar to that of the native cardiotoxin of a defined structure only in aqueous solutions with the presence of calcium ions. Immunoprecipitation assay, using the anti-cardiotoxin V, showed that in the presence of calcium ion the peptide had same cross reaction as that of native cardiotoxin. Hemolysis assay in the presence of calcium ion (150-250mmol) and phospholipase A/sub 2/ showed that the peptide had 65- 70% as much cytolytic activity as the native toxin.
- 英文摘要: --
- 中文關鍵字: Protein Engineering; Disulfide; Novel Conformation; Biological Activity
- 英文關鍵字: 蛋白質工程;雙硫鍵;新奇構形;生物活性