Shiono T
Department of Ophthalmology, Tohoku University School of Medicine, Miyagi, Japan.
Graefes Arch Clin Exp Ophthalmol. 1988;226(6):583-6. doi: 10.1007/BF02169208.
Acid hydrolases (acid phophatase, N-acetyl-beta-D-glucosaminidase, alpha-D-mannosidase, alpha-L-fucosidase, and beta-D-glucuronidase) in the bovine lens epithelium were studied biochemically. p-Nitrophenyl derivatives were used as substrate. All enzymatic activity was found to be much higher in the epithelium than in the cortex and nucleus. The properties of acid phosphatase, N-acetyl-beta-D-glucosaminidase, and alpha-D-mannosidase were also studied, yielding Km values of 0.28, 0.95, and 0.53 mM, respectively. The optimal pH of these enzymes was acidic. Among the subcellular fractions, both acid phosphatase and N-acetyl-beta-D-glucosaminidase had the highest enzymatic activities in the 20,000 g precipitate fraction, while alpha-D-mannosidase showed no difference in activity among the subcellular fractions, suggesting that alpha-D-mannosidase in the bovine lens epithelium is nonlysosomal.
对牛晶状体上皮中的酸性水解酶（酸性磷酸酶、N-乙酰-β-D-氨基葡萄糖苷酶、α-D-甘露糖苷酶、α-L-岩藻糖苷酶和β-D-葡萄糖醛酸酶）进行了生化研究。对硝基苯基衍生物用作底物。发现所有酶活性在上皮中比在皮质和核中高得多。还研究了酸性磷酸酶、N-乙酰-β-D-氨基葡萄糖苷酶和α-D-甘露糖苷酶的特性，其Km值分别为0.28、0.95和0.53 mM。这些酶的最佳pH呈酸性。在亚细胞组分中，酸性磷酸酶和N-乙酰-β-D-氨基葡萄糖苷酶在20,000 g沉淀组分中具有最高的酶活性，而α-D-甘露糖苷酶在亚细胞组分中的活性没有差异，这表明牛晶状体上皮中的α-D-甘露糖苷酶是非溶酶体的。
