摘要
本实验条件下,醛还原酶的最适反应温度为40℃。在25—45℃范围内,K_(iNADPH)随温度上升而增大,K_(mD-)葡萄糖醛酸(K_(mD-Glu))随温度上升而减小,25℃时K_(mNADPH)值最小,反应的活化能为4521±653Cal/mol。温度越高,Alr1的ΔG~≠越大,约3/4的ΔG~≠用以维持过渡态酶一底物复合物的空间构象,以增加分子的有序程度。
Aldehyde reductase is a NADPH-dependent oxidoreductase,obeying a steady-state order bibi mechanism.Under the condition of this experiment the optimum temperature of aldehyde reductase reaction from human placenta was 40℃.Within the range of 25-45℃ KiNADPHincreased and Km-glucuronate decreased along with the raising temperature.At 25℃ the value of KmNADPH was the least.The activation energy of the reaction was 4521±653 cal/mole.The higher the temperature,the larger the △G≠.Three-quarter of △G≠ was used to keep the space-conformation in enzyme-substrate complex under transient condition.
出处
《湖南医科大学学报》
CSCD
1989年第1期1-5,共5页
Bulletin of Hunan Medical University
关键词
醛氧化还原酶
热力学
胎盘
aldehyde oxidoreductases
kinetics
thermodynamics
placenta
human
biochemistry
