RECOMBINANT HUMAN PLACENTAL RIBONUCLEASE INHIBITOR AND ITS PREPARATION

摘要

PROBLEM TO BE SOLVED: To provide a method for preparing protein PRI which specifically inhibit enzyme ribonuclease (RNase) catalyzing the decomposition of RNA and is isolated from human placenta. SOLUTION: When transforming an insoluble crude product expressed within cells through the expression of cDNA encoding active human placental ribonuclease inhibitor within the cells into an active human placental ribonuclease inhibitor by solubilization and regeneration, the method of this invention comprises the following processes: (a) isolating insoluble, inactive human placental ribonuclease inhibitor from the cells by means of the first buffer solution; (b) solubilizing the inactive human placental ribonuclease inhibitor by mixing it with the second buffer solution including urea in a concentration of >=ca. 4 M; (c) diluting human placental ribonuclease inhibitor with the third buffer solution.