| 摘要 |
The expression of polypeptides, in particular biologically functional human placental factor XIII, in a novel yeast expression vector at levels which constitute as much as 2 % protein of the partially purified cell-free extract is disclosed in the present invention. The advantages of the expression vector of the invention are demonstrated using Factor XIII which is the last zymogen to be activated in the vertebrate blood coagulation cascade. The active form, Factor XIIIa, is a transglutaminase that covalently cross-links fibrin molecules by joining gamma-glutamyl and epsilon -lysyl primary amine groups. Prior to the present invention, this important blood coagulation factor was derived from human sera with the potential for contamination inherent in that process. |
