Mueller O T, Little L E, Miller A L, Lozzio C B, Shows T B
Clin Chim Acta. 1985 Aug 30;150(3):175-83. doi: 10.1016/0009-8981(85)90242-6.
The human disorders I-cell disease and pseudo-Hurler polydystrophy (also known as mucolipidosis II and III, respectively) are caused by an inherited deficiency of UDP-GlcNAc: lysosomal enzyme precursor GlcNAc-P transferase activity. The most common genetic variants of these diseases (complementation group A) can be identified in homozygotes and heterozygotes using a GlcNAc-P transferase assay with artificial acceptors and commercially available radiochemicals. The kinetic characteristics of the residual GlcNAc-P transferase activity in complementation group A fibroblasts indicates that the low activity is due to a low Vmax. The measured Michaelis-Menten constants for the substrates UDP-GlcNAc and alpha-methyl mannoside are in the normal range. Homozygotes and heterozygotes of another less common variant of pseudo-Hurler polydystrophy (complementation group C) have normal activity and normal kinetic characteristics with this assay using alpha-methyl mannoside as the acceptor substrate. Several PHP variants with unusual characteristics are discussed.
人类疾病I-细胞病和假胡尔勒氏多营养不良症（也分别称为粘脂贮积症II型和III型）是由UDP-N-乙酰葡糖胺：溶酶体酶前体GlcNAc-P转移酶活性的遗传性缺乏引起的。这些疾病最常见的基因变体（互补组A）可以通过使用人工受体和市售放射性化学物质的GlcNAc-P转移酶测定法在纯合子和杂合子中进行鉴定。互补组A成纤维细胞中残余GlcNAc-P转移酶活性的动力学特征表明，低活性是由于Vmax较低。所测得的底物UDP-N-乙酰葡糖胺和α-甲基甘露糖苷的米氏常数在正常范围内。使用α-甲基甘露糖苷作为受体底物进行此测定时，假胡尔勒氏多营养不良症另一种较不常见变体（互补组C）的纯合子和杂合子具有正常活性和正常动力学特征。文中讨论了几种具有异常特征的假胡尔勒氏多营养不良症变体。
