Regional distribution and substrate specificity of digestive enzymes involved in terminal digestion in Musca domestica hind-midguts.
One membrane-bound alpha-glucosidase and two soluble alpha-glucosidases were isolated from homogenates of the hind-midgut, the main digestive region in Musca domestica larvae. The membrane-bound alpha-glucosidase and the low-Mr soluble alpha-glucosidase hydrolyze maltopentaose better than maltose, maltotriose, and maltotetraose, the reverse being true for the high-Mr soluble alpha-glucosidase. A membrane-bound glucoamylase previously described in Musca domestica midgut was shown by gradient centrifugation and dialysis against EDTA to result from the combined action of an amylase and an alpha-glucosidase. The determination of amylase, alpha-glucosidases, soluble and membrane-bound carboxypeptidase A, membrane-bound aminopeptidase and dipeptidase along the tissue and luminal contents of the hind-midgut is described. The data support a proposal concerned with how starch and protein are digested in Musca domestica larval hind-midguts and where and how midgut glycosidases and peptidases are secreted.
Jordão
B P
BP
Departamento de Bioquímica, Universidade de São Paulo, Brasil.
Terra
W R
WR
D000818:Animals; D004063:Digestion; D006793:Houseflies / Q000201:enzymology* / Q000502:physiology; D006867:Hydrolases / Q000378:metabolism*; D007814:Larva / Q000201:enzymology; D010447:Peptide Hydrolases / Q000378:metabolism; D013379:Substrate Specificity; D000520:alpha-Glucosidases / Q000378:metabolism
D006867:Hydrolases; D000520:alpha-Glucosidases; D010447:Peptide Hydrolases