Abstract
Two fractions of neutral α-glucosidase were partially purified from the insoluble fraction of bovine lens. This is the first report of such an event to the best of our knowledge. The apparent native molecular weights of these fractions were 121 kDa (fraction-I) and 254 kDa (fraction-II). Both fractions contained three polypeptides with molecular weights of 21, 25 and 30kDa, although the proportion of these peptides was different in both fractions. The optimal pH of fraction-I and fraction-II was pH 6.0 and 6.5, and the optimal temperature for both fractions was approximately 50°C. The Km values of fractions-I and -II for 4-methylumbelliferyl-α-glucopyranoside were 0.086, and 0.192mM. The activities of these enzymes were inhibited strongly by HgCl2 and slightly by D-iodoacetic acid, but not by D-turanose. From this, we suggest that the enzyme in the insoluble fraction of bevine lens may be a cytoplasmic neutral α-glucosidase which binds to the cell membrane.
