Glycosidases of normal human donor cornea

Although there have been reports of glycosidases in various ocular tissues, there are very few quantitative data concerning human corneal glycosidases. In this study, the pH optima, apparent Km, and Vmax values were determined for seven glycosidases of human donor corneas obtained from an eye bank. In terms of micromoles of substrate cleaved per milligram of protein per hour, the enzymatic activity of the glycosidases was in the following order of decreasing magnitude: βgalactosaminidase, βglucosaminidase, βgalactosidase, βglucuronidase, αmannosidase, αfucosidase, αglucosidase. The pH optima of the enzymes ranged from 3.4 to 5.7.