Characterization of microvillar membrane proteins of dog small intestine by two-dimensional electrophoresis.
A method for analysing microgram amounts of microvillar membranes by two-dimensional electrophoresis (protein mapping) is described, and has been used to characterize the microvillar proteins of the small intestine of German shepherd, corgi, and beagle dogs. Detergent-solubilized microvillar membranes were radiolabelled with 14C and separated by isoelectric focussing followed by SDS-PAGE. Proteins were detected fluorographically and glycoproteins by lectin-affinity staining. The microvillar hydrolases alkaline phosphatase and dipeptidyl aminopeptidase IV were identified by active-site labelling and aminopeptidase N by immunoprecipitation. Changes following pancreatic duct diversion were consistent with accumulation of pro-sucrase-isomaltase and diminished expression of the sucrase and isomaltase subunits. Cytoskeletal proteins were concentrated in the core fraction remaining after extraction of microvillar membranes with Triton X-100. There were no consistent differences between dogs of different breed, and the canine protein maps were similar to the human.
Pemberton
P W
PW
Department of Gastroenterology, Manchester Royal Infirmary, U.K.
Lobley
R W
RW
Holmes
R
R
Sørensen
S H
SH
Simpson
K W
KW
Batt
R M
RM
D000469:Alkaline Phosphatase / Q000302:isolation & purification; D000818:Animals; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000302:isolation & purification; D018819:Dipeptidyl Peptidase 4 / Q000302:isolation & purification; D004285:Dogs; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D006801:Humans; D007421:Intestine, Small / Q000737:chemistry* / Q000201:enzymology; D007525:Isoelectric Focusing; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000302:isolation & purification; D008565:Membrane Proteins / Q000737:chemistry / Q000302:isolation & purification*; D008832:Microchemistry / Q000379:methods; D008871:Microvilli / Q000737:chemistry* / Q000201:enzymology; D008970:Molecular Weight; D010449:Peptide Mapping; D013045:Species Specificity
D003598:Cytoskeletal Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D000469:Alkaline Phosphatase; D018819:Dipeptidyl Peptidase 4