HETERODIMERIC PROTEIN AND PREPARATION METHOD BASED ON CHARGE NETWORK

摘要

A charge network based heterodimer FC transformation method and Heterodimeric protein preparation method, and protein and polypeptide. On first polypeptide containing a CH3 region and/or the second polypeptide containing a CH3 region of FC, one or more amino acids mutate into positive-charge or negative-charge amino acids, and they contact each other to form an interface promoting the formation of heterodimer. The mutation is one of sense mutations selected and obtained through the following method: 1) the one or more amino acids in the CH3 region of the random mutant antibody FC being amino acids with a positive or negative charge; 2) under the effect of the charge network between the interface amino acids, calculating an impact value of the mutation on homodimer and heterodimer: the mutation impact value=the total charge after the mutation-the total charge before the mutation; the total charge=the sum of sub-network charges of the mutated amino acids, the positive-positive charge interaction being 1, the negative-negative charge interaction being 1, interaction between the positive charge and the negative charge being -1, and interaction between the positive charge and the non-charge or between the negative charge and the non-charge is 0; and 3) selecting the mutations with the impact value on homodimer being greater than or equal to 0, or selecting the mutations with the impact value on heterodimer being less than or equal to 0. The method can promote the formation of heterodimer, and meanwhile suppress the formation of homodimer.