Method for preparing rhCNB dimer

The invention relates to the technical field of biology, in particular to a method for preparing recombinant human calmodulin phosphatase subunit B (short for rhCNB). The method comprises the following steps that 1, rhCNB coarse pure liquid is prepared; 2, on the reaction condition that the pH value ranges from 6.0 to 7.0 and the temperature ranges from 2 DEG C to 15 DEG C, the rhCNB coarse pure liquid is taken and mixed with an oxidizing agent, oxidation is conducted for 12-24 h, and after oxidation is completed, purification and separation are conducted. According to the method for preparing the recombinant human calmodulin phosphatase subunit B (short for rhCNB), a final product is rhCNB dimer, substances such as beta mercaptothanolb, DTT, EGTA are not contained, the technology has innovation and is good in repeatability, purity detection is conducted on a collected protein solution, the content of the dimer is 98 percent or above, and the content of a polymer is smaller than 0.5 percent.