Renal neutral alpha-D-glucosidase has no role in transport of D-glucose derived from maltose hydrolysis.

To reinvestigate the "hydrolase-related transport" concept, neutral alpha-D-glucosidase, a membrane-bound disaccharidase of renal proximal tubule, was first purified from brush-border membranes and then asymmetrically reincorporated into egg phosphatidylcholine vesicles. Proteolytic treatments and immunotitration studies demonstrated that this enzyme was integrated in native and artificial membrane vesicles with a similar topology. The uptake of free glucose and glucose produced by maltose hydrolysis was studied using 1) proteoliposomes containing integrated neutral alpha-D-glucosidase, in combination with other membrane proteins, and 2) proteoliposomes containing only the other membrane proteins but incubated in a medium containing neutral alpha-D-glucosidase in its hydrophilic form.

Oligomeric structure of the sodium-dependent phlorizin binding protein from kidney brush-border membranes.

Immunodetection of solubilized kidney brush-border proteins on Western blots using antibodies against the 70 kDa phlorizin binding component of sodium-glucose cotransporter allows to identify an additional protein band with apparent molecular mass of 120 kDa in the presence of reducing agent dithiothreitol. Antibodies specifically eluted from the 70 kDa protein still recognize the 120 kDa protein on Western blot. The lack of dissociation of the 120 kDa protein from native brush borders or Triton X-100 extract in the presence of dithiothreitol can be improved by an extended incubation at 25 degrees C; this protein is full dissociated when purified by electroelution from polyacrylamide gel and gives two subunits with apparent molecular masses of 70 and 60 kDa by Coomassie staining and Western blot analysis.

[Transplantation of a segmental small intestine in dogs. Comparison between jejunal graft and ileal graft].

The purpose of this study was to compare heterotopic jejunal and ileal allografts in the dog under cyclosporine A. Fourteen allografts (8 ileal and 6 jejunal) were successfully performed. There was no case of graft-versus-host disease in this series.

Jejunal versus ileal segmental allografts in the dog: comparison of immunologic and functional results.

Segmental small-bowel grafts have been advocated as a means of reducing the incidence of rejection and graft-versus-host disease in small-bowel transplant recipients. This study compared the results achieved with heterotopic segmental allografts of the jejunum and the ileum that used 120 cm Thiry-Vella loops in a dog model. Immunosuppressive therapy consisted of 25 mg cyclosporine/kg/day.

Characterization and purification of a guanidinobenzoatase: a possible marker of human renal carcinoma.

Guanidinobenzoatases are cell surface-associated proteinases supposed to be involved in cancer metastasis, cell migration, and tissue remodeling. The main features of the guanidinobenzoatase associated with human renal carcinoma plasma membrane are weak membrane association, continuous cleavage of p-nitrophenyl-p'-guanidinobenzoate conversely to the site titration effect of this compound when used with trypsin, and a peculiar sensitivity to serine protease inhibitors, compatible with a poorly active form. Plasma membrane preparation followed by agmatine-trisacryl affinity chromatography allows the purification of guanidinobenzoatase to homogeneity with an apparent enrichment factor of 450.

[Segmental small intestine transplantation in dogs: comparison between a jejunal graft and an ileal graft].

The aim of this study was to compare segmental grafts of jejunum and ileum in a dog model. 14 segmental grafts, 8 ileal (Il. A) and 6 jejunal (Jej.

Purification and properties of neutral maltase from human granulocytes.

A procedure for the purification of neutral maltase from human polymorphonuclear leukocytes is described, involving solubilization with Triton X-100, proteolytic attack and three chromatographic steps: DEAE ion exchange, AcA 22 gel filtration and a second DEAE chromatography. The enzyme was obtained with a final specific activity of 30 units/mg of protein, comparable with that of other neutral maltases previously purified. The Mr of the enzyme was 550,000 as determined by gel filtration.