Weiss P, Tietze F, Gahl W A, Seppala R, Ashwell G
National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892.
J Biol Chem. 1989 Oct 25;264(30):17635-6.
Sialuria is a rare inborn error of metabolism, the hallmarks of which are moderate developmental retardation, coarse facial features, and an enormous amount of free N-acetylneuraminic acid (sialic acid) in the urine. Until now, the basic biochemical defect in this disorder has remained uncertain. In this report, the activity of the rate-limiting enzyme in the biosynthesis of sialic acid has been measured directly in whole cell lysates by a highly sensitive assay. With this technique, the basic defect in sialuria has been identified unequivocally as the loss of feedback control of uridine diphosphate N-acetylglucosamine 2-epimerase by cytidine monophosphate N-acetylneuraminic acid with resultant overproduction of sialic acid.
唾液酸尿症是一种罕见的先天性代谢缺陷病，其特征为中度发育迟缓、面部特征粗糙以及尿中大量游离的N - 乙酰神经氨酸（唾液酸）。迄今为止，该病症的基本生化缺陷仍不明确。在本报告中，通过一种高灵敏度检测方法直接测定了全细胞裂解物中唾液酸生物合成限速酶的活性。利用这项技术，已明确鉴定出唾液酸尿症的基本缺陷是胞苷单磷酸N - 乙酰神经氨酸对尿苷二磷酸N - 乙酰葡糖胺2 - 表异构酶的反馈控制丧失，从而导致唾液酸过量产生。
