| 摘要 |
PURPOSE:To efficiently obtain the subject active human lysozyme by treating a prescribed solubilized solution of a reduced form human lysozyme in the presence of an oxidation-reduction agent and a reduced concentration of a protein modifier. CONSTITUTION:Microorganisms transformed by a vector containing DNA coding human lysozyme are cultured to obtain an inert human lysozyme solution (A). A protein modifier of 4-6 M such as guanidine hydrochloride and a reducing agent of 0.005-1.0 M such as 2mercaptoethanol are then added to the (A) solution to carry out a solubilization reduction reaction and to obtain a solution (B) of a reduced form human lysozyme. An oxidation-reduction agent (C) is subsequently prepared by mixing cysteine with cystine, etc., in a molar concentration ratio of 1: (5-20). The protein modifier is then added to the (B) solution in the presence of 0.001-0.1M(C) component so that the concentration of the modifier may be (1/10)-(1/3) of that during the reaction. The resultant mixture is kept at pH 6-9 for >=3 hr and the concentration of the protein modifier is subsequently lowered to 0-(1/3). The solution is then agitated for 1-48 hr to obtain a solubilization reduction reaction solution (D) and the obtained (D) component is subsequently purified using the gel filtration method, etc., thus producing the objective active human lysozyme. |
