Glössl J, Kresse H
Clin Chim Acta. 1978 Aug 15;88(1):111-9. doi: 10.1016/0009-8981(78)90157-2.
The trisaccharide 6-sulfo-N-acetylgalactosamine-glucuronic acid-6-sulfo-N-acetyl-[1-3H]galactosaminitol was used as a substrate for the determination of N-acetylgalactosamine-6-sulfate sulfatase activity. The amount of liberated sulfate was measured indirectly by separating monosulfated reaction products from the substrate on Dowex 1 X 2 microcolumns in a simple two step procedure. Fibroblast homogenates from patients with various genotypes, except classical Morquio's disease, released 410 +/- 90 pmol sulfate/h/mg cell protein. The enzyme exhibited a pH optimum of pH 4.8 and a KM of about 1 X 10(-4) mol/1. It was strongly inhibited by phosphate, sulfate and chloride ions. In three cell lines from patients with classical Morquio's disease a residual activity between 1 and 2% of the mean normal activity was found. All cell lines tested released sulfate from 6-sulfo-N-acetylglucosamine-glucuronic acid-[1-3H]-anhydromannitol. Cell extracts from cultured amniotic fluid cells exhibited a N-acetylgalactosamine-6-sulfate sulfatase activity between 120 and 320 pmol/h/mg protein. An enzyme activity of 370 +/- 100 pmol sulfate/h/mg protein was found in peripheral leucocytes from healthy donors. The determination of N-acetyl-galactosamine-6-sulfate sulfatase activity in one family with an affected patient indicated that the enzyme deficiency is also expressed in leucocytes.
三糖6-磺基-N-乙酰半乳糖胺-葡萄糖醛酸-6-磺基-N-乙酰-[1-³H]半乳糖胺醇被用作测定N-乙酰半乳糖胺-6-硫酸酯酶活性的底物。通过在Dowex 1 X 2微柱上以简单的两步法将单硫酸化反应产物与底物分离，间接测量释放的硫酸量。除经典莫尔基奥氏病外，来自各种基因型患者的成纤维细胞匀浆释放出410±90 pmol硫酸/小时/毫克细胞蛋白。该酶的最适pH为4.8，米氏常数约为1×10⁻⁴摩尔/升。它受到磷酸根、硫酸根和氯离子的强烈抑制。在来自经典莫尔基奥氏病患者的三个细胞系中，发现残余活性为正常平均活性的1%至2%。所有测试的细胞系都从6-磺基-N-乙酰葡糖胺-葡萄糖醛酸-[1-³H]-脱水甘露糖醇中释放出硫酸。培养的羊水细胞提取物的N-乙酰半乳糖胺-6-硫酸酯酶活性在120至320 pmol/小时/毫克蛋白之间。在健康供体的外周血白细胞中发现酶活性为370±100 pmol硫酸/小时/毫克蛋白。对一个有患病患者的家庭进行的N-乙酰半乳糖胺-6-硫酸酯酶活性测定表明，该酶缺乏症在白细胞中也有表现。
