In vitro action of human and porcine alpha-amylases on cyclomalto-oligosaccharides.

The vitro action of human and porcine pancreatic alpha-amylases on cyclomalto-oligosaccharides (cyclodextrins) was investigated both by a high-performance liquid chromatographic analysis and a quantitative analysis of the reducing power of cyclodextrin hydrolyzates. Cyclomalto-octaose (gamma-cyclodextrin) was hydrolyzed to produce mainly maltose, but cyclomalto-hexaose and -heptaose were little affected both by human and porcine alpha-amylases. Quantitative analysis of reducing power revealed that the ring-opening rate of gamma-cyclodextrin catalyzed by human pancreatic alpha-amylase was 2.8 times slower than that catalyzed by the porcine enzyme. The number of multiple attacks on gamma-cyclodextrin and its inhibitor constants for human pancreatic alpha-amylase and porcine pancreatic alpha-amylase were almost the same.