Subcellular fractionation of midgut cells of the sunn pest Eurygaster integriceps (Hemiptera: Scutelleridae): enzyme markers of microvillar and perimicrovillar membranes.
The subcellular distributions of six digestive and non-digestive enzymes (alpha-glucosidase, beta-glucosidase, alkaline phosphatase, acid phosphatase, aminopeptidase and lactate dehydrogenase) of Eurygaster integriceps have been studied. The subcellular distributions of acid phosphatase and alpha-glucosidase are similar and the gradient ultracentrifugation profiles of these two enzymes overlap. Two partially membrane-bound enzymes, alkaline phosphatase and beta-glucosidase have similar distributions in differential centrifugation fractions, which are different from that of alpha-glucosidase. Sucrose gradient ultracentrifugation of membranes from luminal contents showed that beta-glucosidase carrying membranes are heavier. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the profile of proteins extracted from beta-glucosidase carrying membranes is different from that of alpha-glucosidase carrying membranes. We conclude that beta-glucosidase and aminopeptidase are markers of microvillar membrane (MM) and perimicrovillar space, respectively, while alpha-glucosidase and acid phosphatase are perimicrovillar markers. In E. integriceps V1 luminal content is a rich source of PMM and MM and that is used to resolve these membranes.
Allahyari
M
M
Department of Plant pests and Diseases, Fars Agriculture and Natural Resources Research Center, Shiraz, Iran.
Bandani
A R
AR
Habibi-Rezaei
M
M
D000626:Aminopeptidases / Q000032:analysis / Q000378:metabolism; D000818:Animals; D002458:Cell Fractionation; D002462:Cell Membrane / Q000737:chemistry / Q000201:enzymology*; D004064:Digestive System / Q000737:chemistry / Q000201:enzymology; D005260:Female; D005959:Glucosidases / Q000032:analysis / Q000378:metabolism; D006430:Hemiptera / Q000737:chemistry* / Q000166:cytology / Q000201:enzymology* / Q000254:growth & development; D019476:Insect Proteins / Q000032:analysis / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000032:analysis / Q000378:metabolism; D008871:Microvilli / Q000737:chemistry / Q000201:enzymology; D010744:Phosphoric Monoester Hydrolases / Q000032:analysis / Q000378:metabolism; D021381:Protein Transport
D019476:Insect Proteins; D007770:L-Lactate Dehydrogenase; D010744:Phosphoric Monoester Hydrolases; D005959:Glucosidases; D000626:Aminopeptidases