三种对磷酸烯醇式丙酮酸（PEP）亲和力增加的丙酮酸激酶变体。

Three pyruvate kinase variants with increased affinity for PEP.

作者信息

Elder G E, Lappin T R, Lawson B E, Bridges J M

出版信息

Br J Haematol. 1981 Mar;47(3):371-81. doi: 10.1111/j.1365-2141.1981.tb02804.x.

DOI:10.1111/j.1365-2141.1981.tb02804.x

Abstract

Three variants of pyruvate kinase are described which have marked reduction of activity associated with severe non-spherocytic haemolytic anaemia. Each variant shows a reduced K0.5 PEP (the value of the intercept of the abscissa on the Hill plot) and reduced Hill coefficient; FDP activation and ATP inhibition are less than normal and utilization of GDP is increased. The variants are slightly less inhibited by 2,3DPG than controls but require more FDP to relieve this inhibition. Cases 1 and 2 have decreased thermostability but case 3 is normal. The mutant enzymes are further distinguished by their affinity for FDP. Their kinetic and physicochemical properties are compared with other known cases with high affinity for PEP and discussed in terms of a R in equilibrium to T model model for allosteric enzymes.

摘要

已描述了丙酮酸激酶的三种变体，它们的活性显著降低，并伴有严重的非球形红细胞溶血性贫血。每种变体的K0.5 PEP（希尔图横坐标截距值）降低，希尔系数降低；果糖二磷酸（FDP）激活和三磷酸腺苷（ATP）抑制低于正常水平，二磷酸鸟苷（GDP）利用率增加。这些变体受2,3-二磷酸甘油酸（2,3DPG）的抑制比对照略小，但需要更多的FDP来解除这种抑制。病例1和病例2的热稳定性降低，但病例3正常。突变酶还因其对FDP的亲和力而有所区别。将它们的动力学和物理化学性质与其他对磷酸烯醇丙酮酸（PEP）具有高亲和力的已知病例进行了比较，并根据变构酶的R态与T态平衡模型进行了讨论。