Kelson T L, Secor McVoy J R, Rizzo W B
Department of Human Genetics, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298, USA.
Biochim Biophys Acta. 1997 Apr 17;1335(1-2):99-110. doi: 10.1016/s0304-4165(96)00126-2.
To better understand the genetic disorder Sjogren-Larsson syndrome which is caused by a deficiency of fatty aldehyde dehydrogenase activity, we determined the subcellular localization of the enzyme and investigated its biochemical properties. Using density gradient centrifugation, we found that fatty aldehyde dehydrogenase activity was predominantly localized in the microsomal fraction in human liver. This fatty aldehyde dehydrogenase was solubilized from human liver microsomes and purified by chromatography on columns consisting of omega-aminohexyl-agarose and 5'-AMP-Sepharose 4B. The enzyme had an apparent subunit molecular weight of 54000, required NAD+ as cofactor, had optimal activity at pH 9.8, and was thermolabile at 47 degrees C. Fatty aldehyde dehydrogenase had high activity towards saturated and unsaturated aliphatic aldehydes ranging from 6 to 24 carbons in length, as well as dihydrophytal, a 20-carbon branched chain aldehyde. In contrast, acetaldehyde, propionaldehyde, crotonaldehyde, glutaraldehyde, benzaldehyde, and retinaldehyde were poor substrates. The enzyme was inhibited by disulfiram, iodoacetamide, alpha,p-dibromoacetophenone, and p-chloromercuribenzoate. These results indicate that microsomal fatty aldehyde dehydrogenase is a distinct human aldehyde dehydrogenase isozyme that acts on a variety of medium- and long-chain aliphatic substrates.
为了更好地理解由脂肪醛脱氢酶活性缺乏引起的遗传性疾病舍格伦 - 拉松综合征，我们确定了该酶的亚细胞定位并研究了其生化特性。通过密度梯度离心，我们发现脂肪醛脱氢酶活性主要定位于人肝脏的微粒体部分。这种脂肪醛脱氢酶从人肝脏微粒体中溶解出来，并通过在由ω-氨基己基琼脂糖和5'-AMP-琼脂糖4B组成的柱上进行色谱纯化。该酶的表观亚基分子量为54000，需要NAD +作为辅因子，在pH 9.8时具有最佳活性，并且在47℃下不耐热。脂肪醛脱氢酶对长度为6至24个碳的饱和和不饱和脂肪醛以及二氢植醇（一种20碳支链醛）具有高活性。相比之下，乙醛、丙醛、巴豆醛、戊二醛、苯甲醛和视黄醛是较差的底物。该酶被双硫仑、碘乙酰胺、α，p-二溴苯乙酮和对氯汞苯甲酸抑制。这些结果表明微粒体脂肪醛脱氢酶是一种独特的人醛脱氢酶同工酶，作用于多种中链和长链脂肪族底物。
