Freeman C, Hopwood J J
Department of Chemical Pathology, Adelaide Children's Hospital, South Australia, Australia.
Anal Biochem. 1989 Feb 1;176(2):244-8. doi: 10.1016/0003-2697(89)90303-5.
N-Acetylglucosamine-6-sulfatase activity was assayed by incubation of the radiolabeled disaccharide O-(a-N-acetylglucosamine-6-sulfate)-(1----3)-L-[6-3H]-idonic acid (GlcNAc6S-IdOA), with homogenates of leucocytes, cultured fibroblasts, and urine from normal individuals, patients affected with N-acetylglucosamine-6-sulfatase-deficiency (Sanfilippo D syndrome, mucopolysaccharidosis type IIID), and patients affected with other mucopolysaccharidoses and lysosomal storage disorders. The assay clearly distinguished affected homozygotes from their obligate heterozygotes and normal controls and other lysosomal storage disorders. Sulfatase activity in fibroblasts, leucocytes, and urine toward GlcNAc6S-IdOA exhibited a pH optimum at 4.2, 4.5, and 5.1, respectively. Sulfatase activity in fibroblasts had an apparent Km of 7.2 microM and was significantly inhibited by both sulfate and phosphate ions. The action of fibroblast or leucocyte N-acetylglucosamine-6-sulfatase activity toward GlcNAc6S-IdOA is recommended for the routine enzymatic detection and classification of mucopolysaccharidosis type IIID patients.
通过将放射性标记的二糖O-(α-N-乙酰氨基葡萄糖-6-硫酸盐)-(1→3)-L-[6-³H]-艾杜糖酸（GlcNAc6S-IdOA）与正常个体、患有N-乙酰氨基葡萄糖-6-硫酸酯酶缺乏症（Sanfilippo D综合征，IIID型粘多糖贮积症）的患者、患有其他粘多糖贮积症和溶酶体贮积症的患者的白细胞匀浆、培养的成纤维细胞及尿液一起温育，来测定N-乙酰氨基葡萄糖-6-硫酸酯酶活性。该测定法能清楚地区分患病纯合子与其必然的杂合子以及正常对照和其他溶酶体贮积症。成纤维细胞、白细胞及尿液中针对GlcNAc6S-IdOA的硫酸酯酶活性分别在pH 4.2、4.5和5.1时表现出最佳活性。成纤维细胞中的硫酸酯酶活性的表观Km为7.2微摩尔，且受到硫酸根离子和磷酸根离子的显著抑制。推荐将成纤维细胞或白细胞的N-乙酰氨基葡萄糖-6-硫酸酯酶对GlcNAc6S-IdOA的活性作用用于IIID型粘多糖贮积症患者的常规酶学检测和分类。
