High level expression of active human prothrombin in a vaccinia virus expression system.

We have worked out an efficient and time saving procedure for the expression of recombinant human prothrombin. The glycoprotein was expressed in the vaccinia virus expression system in several mammalian cell lines. The kidney cell lines Vero and BHK and the human cell line Hela were found to efficiently secrete prothrombin. Expression level of 3-4 micrograms of factor II per 10(6) cells per day corresponding to 18-23 mU per 10(6) cells per day were achieved. Since the expression levels obtained with the vaccinia virus/Vero cell system were comparable to those obtained in amplified transformed CHO cells it provides an alternative system for the efficient expression of human prothrombin and may allow to further elucidate structure-function relationships of (pro)thrombin and its various effectors.