A New α-d-Mannosidase Occurring in Golgi Membranes

作者：Béatrice Dewald, Oscar Touster, With the technical assistance of Vera Coleman · 发表于：Journal of Biological Chemistry · 年份：1973 · DOI：10.1016/s0021-9258(19)43382-6 · 被引用次数：138 · 研究领域：Lysosomal Storage Disorders Research、Carbohydrate Chemistry and Synthesis、Glycosylation and Glycoproteins Research

Abstract α-d-Mannosidase has been found to be a component of Golgi membranes of rat liver, other glycosidases being of low or negligible activity except for N-acetyl-β-d-glucosaminidase, which is readily released from the membranes by 0.4 m NaCl. The mannosidase is not appreciably extracted from the membranes by 0.4 m NaCl or by 1% Triton X-100 but is released by 0.5% deoxycholate. In addition to its distinctive subcellular localization, the Golgi enzyme is clearly distinguishable from the lysosomal and soluble cytoplasmic α-d-mannosidases on the basis of pH optimum, mobility in polyacrylamide gel electrophoresis, thermal inactivation rate, and kinetic properties. Possible relationships of the Golgi mannosidase to glycoprotein metabolism and to the other mannosidases are discussed.