trehalose + H2O => 2 D-glucose

Extracellular trehalose, a disaccharide, is cleaved by trehalase associated with the plasma membrane to yield two molecules of glucose. Trehalase has been purified to homogeneity from rabbit intestine and shown to be a monomer attached to the plasma membrane by a GPI anchor (Galand 1984; Ruf et al. 1990). A human cDNA encoding a closely homologous protein has been cloned and its protein product has been shown to have trehalase activity in vitro (Ishihara et al. 1997). The human enzyme has not been characterized further, and so both the posttranslational modifications of the human enzyme and its activity in vivo have been inferred from the properties of the well studied rabbit enzyme.<p>Trehalase deficiency has been described in two isolated cases in Europe (Bergoz 1971; Madzarovovà-Nohejlova 1973) and at high frequency in a population of Greenland natives (Gudmand-Hoyer et al. 1988) but molecular defects responsible for the deficiency have not yet been described so it is not annotated in Reactome.

细胞外海藻糖，一种二糖，由与质膜关联的海藻糖酶分解，产生两个葡萄糖分子。海藻糖酶已从兔肠道中纯化至均一性，并证实其为通过GPI锚定连接至质膜的单体（Galand 1984；Ruf 等人，1990年）。一种编码与海藻糖酶高度同源蛋白的人源cDNA已被克隆，其蛋白质产物在体外表现出海藻糖酶活性（Ishihara 等人，1997年）。然而，人类酶的性质尚未进一步研究，因此，人类酶的翻译后修饰及其在体内的活性均从已深入研究过的兔酶特性中推断而来。<p>海藻糖酶缺乏症在欧洲已描述在两个孤立病例中（Bergoz 1971；Madzarovovà-Nohejlova 1973），在格陵兰原住民群体中高频率出现（Gudmand-Hoyer 等人，1988年），但导致缺乏症的分子的缺陷尚未被描述，因此尚未在Reactome中标注。