文章基本信息

标题：The subcellular localization of neutral sphingomyelinase in rat liver.
本地全文：下载
作者：K Y Hostetler ; P J Yazaki
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：1979
卷号：20
期号：4
页码：456-463
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：The subcellular distribution of neutral sphingomyelinase activity has been determined in rat liver. Neutral sphingomyelinase is present in the plasma membrane. This enzyme requires either Mg2+ or Mn2+ for full activity; these cations cannot be replaced by Co2+ or Ca2+. The plasma membrane sphingomyelinase is strongly inhibited by Hg2+. A small amount of neutral spingomyelinase activity appears to be present in microsomes. No neutral sphingomyelinase activity is present in liver mitochondria or bytosol. Lysosomal sphingomyelinase is fully active at pH 4.4--4.8 without added divalent cations. However, between pH 5.0 and 7.5 lysosomal sphingomyelinase activity is stimulated by Mg2+, Mn2+, Co2+, and Ca2+. Below pH 4.8, Mg2+ inhibits the reaction. In contrast to the results obtained with the neutral sphingomyelinase activity of plasma membranes and microsomes, lysosomal sphingomyelinase is unaffected by sulfhydryl inhibitors.