HS小鼠肝脏醛脱氢酶的亚细胞分布及动力学参数

Subcellular distribution and kinetic parameters of HS mouse liver aldehyde dehydrogenase.

Little R G, Petersen D R

Comp Biochem Physiol C Comp Pharmacol Toxicol. 1983;74(2):271-9. doi: 10.1016/0742-8413(83)90101-9.

Abstract

Aldehyde dehydrogenase subcellular distribution studies were performed in a heterogeneous stock (HS) of male and female mice (Mus musculus) with propionaldehyde (5 mM and 50 microM) and formaldehyde (1 mM) and NAD+ or NADP+. 2. The relative percents of distribution were: cytosolic 55-68%, mitochondrial 12-20%, microsomal 9-18% and lysosomal 3-15% for both propionaldehyde concentrations and NAD+. 3. Kinetic experiments using propionaldehyde and acetaldehyde with NAD+ revealed two separate enzymes, Enzyme I (low Km) and Enzyme II (high Km) in the cytosolic and mitochondrial fractions. 4. The kinetic data also indicated a spectrum of cytosolic low Km values that exhibited a bimodal distribution with one congruent to 40 microM and one congruent to 5 microM. 5. It was concluded that there was no significant difference in aldehyde-metabolizing capability between male and female HS mice, compared on a per gram of liver basis. The cytosolic low Km enzyme plays a major role in aldehyde oxidation at moderate to low aldehyde concentrations.

摘要

利用丙醛（5 mM和50 microM）、甲醛（1 mM）以及NAD⁺或NADP⁺，在雄性和雌性小鼠（小家鼠）的异种群体（HS）中进行了醛脱氢酶亚细胞分布研究。2. 对于两种丙醛浓度和NAD⁺，分布的相对百分比为：胞质55 - 68%、线粒体12 - 20%、微粒体9 - 18%以及溶酶体3 - 15%。3. 使用丙醛和乙醛与NAD⁺进行的动力学实验表明，在胞质和线粒体部分存在两种不同的酶，酶I（低Km）和酶II（高Km）。4. 动力学数据还表明，胞质低Km值呈现出双峰分布，一个与40 microM一致，另一个与5 microM一致。5. 得出的结论是，以每克肝脏为基础比较时，雄性和雌性HS小鼠在醛代谢能力上没有显著差异。胞质低Km酶在中低醛浓度下的醛氧化中起主要作用。