@article {573681, title = {Specificity studies on alpha-mannosidases using oligosaccharides from mannosidosis urine as substrates}, journal = {Biochim Biophys Acta}, volume = {410}, number = {1}, year = {1975}, month = {1975 Nov 20}, pages = {156-63}, abstract = {Oligosaccharides containing terminal non-reducing alpha(1 leads to 2)-, alpha(1 leads to 3)-, and alpha(1 leads to 6)-linked mannose residues, isolated from human and bovine mannosidosis urines were used as substrates to test the specificities of acidic alpha-mannosidases isolated from human and bovine liver. The enzymes released all the alpha-linked mannose residues from each oligosaccharide and were most effective on the smallest substrate. Enzyme A in each case was less active on the oligosaccharides than alpha-mannosidase B2, even though the apparent Km value for the substrates was the same with each enzyme. The human acidic alpha-mannosidases were also found to be more active on substrates isolated from human rather than bovine mannosidosis urine. Human alpha-mannosidase C, which has a neutral pH optimum when assayed with a synthetic substrate, did not hydrolyse any of the oligosaccharides at neutral pH, but was found to be active at an acidic pH.}, keywords = {Animals, Carbohydrate Metabolism, Inborn Errors, Cattle, Disaccharidases, Humans, Hydrogen-Ion Concentration, Kinetics, Liver, Mannose, Mannosidases, Oligosaccharides, Species Specificity}, issn = {0006-3002}, author = {Hultberg, B and Lundblad, A and Masson, P K and Ockerman, P A} }