Huang I Y, Fujii H, Yoshida A
Hemoglobin. 1980;4(5-6):601-9. doi: 10.3109/03630268008997730.
Complete amino acid sequence of normal human phosphoglycerate kinase (PGK) was determined. The enzyme consists of 417 amino acid residues with acetylserine at the NH2-terminal and isoleucine at the COOH-terminal. The structural abnormality of PGK-II, which is fairly common in Southern Pacific populations, is a single amino acid substitution from threonine in the normal enzyme to asparagine in the variant enzyme at the 352nd position. The substitution induced no change in the enzyme activity, but induced strong binding of the variant enzyme with citrate. The structural abnormality of PGK-München is a single amino acid substitution from aspartic acid in the normal enzyme to asparagine in the variant enzyme at the 267th position. PGK-München is associated with red cell enzyme deficiency (about 20% of normal), and substantial heat instability. Therefore, the negative charge of an aspartyl residue at the 267th position must play a role in maintaining the stability of the enzyme molecule. Possible mechanisms of hemolysis due to hereditary deficiency of PGK are discussed.
测定了正常人磷酸甘油酸激酶（PGK）的完整氨基酸序列。该酶由417个氨基酸残基组成，氨基末端为乙酰丝氨酸，羧基末端为异亮氨酸。PGK-II的结构异常在南太平洋人群中相当常见，是正常酶中第352位的苏氨酸被变体酶中的天冬酰胺单氨基酸取代。这种取代没有引起酶活性的变化，但导致变体酶与柠檬酸盐的强结合。PGK-慕尼黑型的结构异常是正常酶中第267位的天冬氨酸被变体酶中的天冬酰胺单氨基酸取代。PGK-慕尼黑型与红细胞酶缺乏（约为正常水平的20%）以及明显的热不稳定性有关。因此，第267位天冬氨酰残基的负电荷必定在维持酶分子的稳定性中起作用。讨论了由于PGK遗传性缺乏导致溶血的可能机制。
