Periplasmic aminopeptidase II of yeast was isolated from protoplast supernatants by ammonium sulfate precipitation, DEAE-Sephacel chromatography and affinity chromatography on immobilized bestatin. This isolation method is more rapid than conventional procedures and, in addition, avoids contact of the enzyme with yeast proteinases. Thus the preparation obtained is likely to represent the native...

The binding of antibodies to podocytic antigens such as the Heymann antigen or aminopeptidase A may lead to the induction of a membranous glomerulonephritis in several species. To study the possible future interactions of antibodies with antigens on these podocytes, epithelial cells from isolated mouse glomeruli were cultured. By indirect immunofluorescence, the cells were positive for cytokera...

Succinyl-Leu-Leu-Val-Tyr-7-amido-4-methylcoumarin (Suc-LLVY-AMC), a fluorogenic endopeptidase substrate, is used to detect 20 S proteasomal activity from Archaea to mammals. An o-phenanthroline-sensitive Suc-LLVY-AMC hydrolyzing activity was detected in Escherichia coli although it lacks 20 S proteasomes. We identified PepN, previously characterized as the sole alanine aminopeptidase in E. coli...

Campylobacter pylori (C. pyloridis) is a fastidious organism found in the gastric mucosa associated with histological gastritis and peptic ulceration. A rapid identification scheme that detects the presence of preformed enzymes (Rosco Diagnostica, Taastrup, Denmark) was applied to clinical isolates of C. pylori. The isolates tested were a very homogeneous group. They all produced oxidase, catal...

A procedure is described for the purification of a neutral protease from fermentation broths of Vibrio proteolyticus. The key feature of the purification scheme is the selective, irreversible inactivation of a contaminating exoenzyme, aminopeptidase, by alkali treatment, rather than removal of this enzyme by conventional chromatographic methods. Fermentation broths or concentrates were brought ...

The p53 tumour suppressor has an important role in cancer cells. Here we show that p53 regulates expression of major histocompatibility complex I on the cell surface. We show that the tumour cell line HCT116, which lacks p53 exhibits significantly lower major histocompatibility complex I expression than its wild-type counterpart. Using a combination of chromatin immunoprecipitation sequencing a...

1. The effects of Concanavalin A (Con A) on enzymes from the intestinal brush border were studied using membrane vesicles (BBMV) prepared from 3- and 6-week-old broiler chickens. 2. Maltase, sucrase, phytase, alkaline phosphatase and leucine aminopeptidase activities were assayed in BBMV in the absence (T0) or presence (T1) of Con A, or in the presence of casein (T2). Disaccharidase specific ac...