Yoshida K, Yanagisawa N
Department of Medicine (Neurology), Shinshu University School of Medicine.
Nihon Rinsho. 1995 Dec;53(12):2973-81.
Glycoprotein consist of oligosaccharides chains covalently attached to the polypeptide backbone. They are synthesized by two pathways; sugar nucleotide pathway and dolichol pathway. The degradation of glycoproteins occurs predominantly in the lysosomes through the ordered actions of lysosomal proteases, glycosidases, and aspartylglucosaminidase. Genetic deficiencies of these enzymes cause progressive accumulation of partially degraded oligosaccharides and glycopeptides, resulting in specific lysosomal storage diseases. Clinically, the diseases are characterized by the various degree of mental retardation, coarse facies, dysostosis multiplex, and visceromegaly. Although the urinary screening test for storage compounds is highly supportive, the definitive diagnosis of the disease is based on the measurement of lysosomal enzyme activity. This paper presents the review of clinical and biochemical features of this group of diseases including alpha-mannosidosis, beta-mannosidosis, fucosidosis, sialidosis, and aspartylglucosaminuria. Recent advances in molecular genetics in fucosidosis and aspartylglucosaminuria are also reviewed.
糖蛋白由共价连接到多肽主链上的寡糖链组成。它们通过两条途径合成：糖核苷酸途径和多萜醇途径。糖蛋白的降解主要发生在溶酶体中，通过溶酶体蛋白酶、糖苷酶和天冬氨酰葡糖胺酶的有序作用进行。这些酶的基因缺陷会导致部分降解的寡糖和糖肽逐渐积累，从而引发特定的溶酶体贮积病。临床上，这些疾病的特征是不同程度的智力迟钝、面容粗糙、多发性骨发育异常和内脏肿大。尽管对贮积化合物的尿液筛查试验具有高度支持作用，但该疾病的确诊仍基于溶酶体酶活性的测定。本文综述了这组疾病的临床和生化特征，包括α-甘露糖苷贮积症、β-甘露糖苷贮积症、岩藻糖苷贮积症、唾液酸贮积症和天冬氨酰葡糖胺尿症。还综述了岩藻糖苷贮积症和天冬氨酰葡糖胺尿症在分子遗传学方面的最新进展。
