Exoglycosidases modify carbohydrate epitopes on glycoproteins and glycolipids. The N-acetyl-α-D-galactosaminidase from the domestic chicken, Gallus domesticus, is an important exoglycosidase which degrades the human blood group A epitope. This enzyme has never been demonstrably purified or thoroughly characterized. We have developed a technique to purify this enzyme to homogeneity. The isolated enzyme has a molecular weight of 49.1 kDa by SDS PAGE and 145.0 kDa by gel filtration. The enzyme is highly selective for PNP-N-acetyl-α-D-galactosaminide and is inactive against other low molecular weight substrates. The enzyme hydrolyzes the terminal N-acetyl-α- D-galactosaminide residues from blood group A2 erythrocytes. Protease activity is below detectable limits. The enzyme has a pH optima of 3.7, a pI of 8.15, is relatively unaffected by ionic strength, and is stable at 4°C.
|Original language||English (US)|
|Number of pages||10|
|State||Published - Jan 1 1992|
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