[Expression and biochemical characterization of human G6PD gene 1376 and 1388 mutation in G6PD-deficient Escherichia...

Nine types of human G6PD gene mutated at the positions of nt 1376 and nt 1388 by site-directed mutagenesis were transformed into the strain of G6PD dificent E. coli HB 351(DE3). The mutated gene was expressed successfully and the enzyme kinetic studies undertaken according to WHO standardization. The results showed that the arginine residues at the positions of 459 and 463 of G6PD gene play an important role in maintaining activity of the enzyme. The amino acid structure, polarity, and electronic property may be responsible for it. The arginine residues at the positions of 459 and 463 are also important for the enzyme-NADP+ binding, but it was not interfered by the lysine-arginine substitution. By inducing a non-sense mutation, it was further demonstrated that the amino acids residueds behind the position of 459 were extremely significant for G6PD activity.