Sucrose a-D-glucohydrolase

Oligo-1,6-D-glucosidase-sucrose a-D-glucohydrolase ( sucrase-isomaltase ) is an intestinal membrane enzyme consisting of two active moieties, each with its hydrolytic site available for nutrient digestion at the luminal-cell interface. 

The concurrent action of sucrose a-D-glucohydrolase and oligo-l,6-D-gluco-sidase active sites of the hybrid oligo-l,6-D-glucosidase-sucrose a-D-glucohydrolase ( sucrose-isomaltase ) from rat intestine on an a-limit dextrin was studied by use of 6 -maltotriosylmaltotriose isolated from the products of controlled action of pullulanase on pullulan (see p. 522). ... 

Electrophoresis on polyacrylamide gels of materials from brush-border membranes of siblings with a deficiency of sucrose a-D-glucohydrolase-oligo-1,6-D-glucosidase ( sucrase - isomaltase ) did not reveal the normal protein band associated with the complex. ... 

Treatment of closed, right-side-out vesicles of porcine, rabbit, and rat jejunum brush borders with papain and Triton X-100 released a sucrose a-D-glucohydrolase that had been bound to the membrane without grossly aifecting the lipid bilayers limiting the vesicles. It was concluded that intestinal sucrose a-D-glucohydrolase is attached to the outside of the membrane. 

The jS-D-fructofuranosidase (see also sucrose a-D-glucohydrolases) released from the vesicles of human intestinal brush-border membranes by various enzymes, particularly pancreatic proteases, has been studied. The results were discussed in terms of the location and chemical binding of the jS-o-fructofuranosidase. 

Amino-acid sequences around the essential carboxylic acid group in the active sites of the sucrose a-D-glucohydrolase oligo-l,6-glucosidase (sucrase-isomaltase) complex of rabbit small intestines have been determined by selective labelling with [ H]conduritol-B epoxide. ... 

The rate of synthesis of sucrose a-D-glucohydrolase is decreased in the small intestines of thyroidectomized and adrenalectomized rats. ... 

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