Yeast aminopeptidase I, when purified from autolysates of brewer's yeast, is obtained in two molecular froms a) the enzymatically active dodecameric complex (Mr = 640,000, s20,w = 22 S) and b) inactive hexamers (Mr = 320,000, s20,w = 12 S). Although the amino acid composition of the 12 S protein is very similar to that of the active enzyme,the hexamers behave differently in ionic exchange chrom...

Leucine aminopeptidase and aminopeptidase M have been covalently bound to an arylamine derivative of porous glass. The bound forms of both enzymes retain 100% of their activities at saturating levels of substrate (leucine p-nitroanilide). For the hydrolysis at pH 7.3 and 25” kcat values for bound and free leucine aminopeptidase are 46 & 5 s-l and 46 + 2 s-l, respectively; for aminopeptidase M (...

1. A method for the preparation of brush border from rabbit kidneys is described. Contamination by other organelles was checked by electron microscopy and by the assay of marker enzymes and was low. 2. Seven enzymes, all hydrolases, were substantially enriched in the brush-border preparation and are considered to be primarily located in this structure. They are: alkaline phosphatase, maltase, t...

The hydrolase aminopeptidase A is an important regulator of the renin-angiotensin system, since it inactivates its most vasoactive component angiotensin II (Ang II). A single i.v. injection of a monoclonal antibody against mouse aminopeptidase A (ASD-4) induces a membranous-like glomerulonephritis in mice, characterized by an acute albuminuria, that is not dependent on complement, the coagulati...

Inactivation of Pseudomonas aeruginosa phpA, encoding a putative leucine aminopeptidase, results in increased transcription of algD. The homologous protein in Escherichia coli, PepA, is multifunctional, possessing independent aminopeptidase and DNA-binding activities. Here we provide in vitro evidence that PhpA is an aminopeptidase and show that this activity is the relevant property with regar...

Sonicates of mouse bone marrow-derived mast cells (BMMC) differentiated in vitro and of mouse serosal mast cells differentiated in vivo contained small but approximately equal amounts of aminopeptidase activity, as determined by cleavage of leucine-beta-naphthylamide and resolution of the reaction products by reverse-phase high-performance liquid chromatography. Aminopeptidase activity was exoc...

The distribution and aminopeptidase activity of prokaryotes were investigated along a natural continuous salinity gradient in a hypersaline coastal lagoon, the Coorong, South Australia. The abundance of prokaryotes significantly increased from brackish to hypersaline waters and different sub-populations, defined by flow cytometry, were observed along the salinity gradient. While four sub-popula...

Activities of various hydrolytic enzymes were determined in rat organ homogenates and on the surface of cells from various sources, i.e., tumor cell strains, primary cultured cells, normal cells, and their transformants. Alanine, leucine, methionine, phenylalanine, and glycyl-proline aminopeptidases and esterase showed relatively high activities in all these organs and cells. In the kidney homo...

The aminopeptidase activity of Phaseolus vulgaris seeds was measured using L-Leu-p-nitroanilide and the L-aminoacyl-ss-naphthylamides of Leu, Ala, Arg and Met. A single peak of aminopeptidase activity on Leu-ss-naphthylamide was eluted at 750 microS after gradient elution chromatography on DEAE-cellulose of the supernatant of a crude seed extract. The effluent containing enzyme activity was app...