摘要
测定了豌豆(Pisum sativum)幼苗的重组叶绿体中光还原的硫氧还蛋白(Td)对6-磷酸葡萄糖脱氢酶(G6PDH)的钝化作用.结果表明,Td在叶绿体G6PDH的光抑制和暗激活中均起重要的调节作用.在其绿色叶片和黄化组织中,G6PDH都存在着两种同工酶,但二硫苏糖醇(DTT)和Td对黄化幼苗中G6PDH活性的影响与叶绿体的明显不同,DTT对黄化幼苗G6PDH的钝化作用和氧化Td的活化作用均低于对叶绿体中的这两种作用.
The activity of glucose-6-phosphate dehydrogenase (G6PDH,E- C.1.1.1.49) in a reconsitu- ted pea chloroplast system was assayed spectrophotometrically by the reduction of NADP,using glucose-6-phosphate as substrate.Deactivation of G6PDH could be intensified by adding light- reduced thioredoxin (Td) into the reconstituted chloroplast system.The experimental restults presented suggest that Td plays an important role not only in the dark activation,but also in the fight deactivation of G6PDH in chloroplasts.There were two isozymes of G6PDH in green and in etiolated pea seedlings.The effects of dithiothreitol (DTT) and Td on G6PDH in etio- lated seedlings were different from that in chloroplasts.The light regulation of G6PDH in chloroplasts is mediated through Td.
基金
国家自然科学基金
关键词
光还原
硫氧还蛋白
葡萄糖脱氢酶
Deactivation
Glucose-6-phosphate dehydrogenase
Thioredoxin
