Effect of deglycosylation of polymannose chains on the properties of yeast external invertase

α-Mannosidase from Cellulomonas sp. released about 70% of the polymannose chains from yeast external invertase. Native and mannose-depleted yeast invertases were compared with regard to various enzymatic properties. It was found that their catalytic activity and thermal and pH stability were identical. However, the mannose-depleted invertase was more sensitive to proteinases such as pronase and subtilisin. The mannose-depleted invertase was less stable than the native enzyme when incubated with sodium dodecyl sulfate. These results show that the polymannose chains of yeast invertase contribute to the high stability of the enzyme.