Human glucose-6-phosphate dehydrogenase: structure and function of normal and variant enzymes.

Glucose-6-phosphate dehydrogenase (G6PD) is a unique enzyme with many genetic variants. Recent progress in molecular biological techniques have provided several important findings about the structure-function relationship of human G6PD. A putative substrate glucose-6-phosphate binding (around Lys 205) and a putative 'structural' NADP binding site (around Lys 386) have been identified. A conservative segment (amino acid 38-44) near the N-terminus was proposed to be the possible second NADP binding region (amino acid 38-44). Analysis of amino acid substitutions of variants revealed that there might be some relationship between the position of substitution and the properties of variants.