-The interactions between organic matter, bacterial biomass, enzyme activities and environmental factors were studied during bank filtration of humus-rich lake water. The exoenzymatic //-glucosidase, phosphatase and alanine-aminopeptidase activities in water were measured in vitro as release of fluorescing degradation products from methylumbelliferyl substrates. The total enzymatic decompositio...

The DmpA (d-aminopeptidase A) protein produced by Ochrobactrum anthropi hydrolyses p-nitroanilide derivatives of glycine and d-alanine more efficiently than that of l-alanine. When regular peptides are utilized as substrates, the enzyme behaves as an aminopeptidase with a preference for N-terminal residues in an l configuration, thus exemplifying an interesting case of stereospecificity reversa...

Ochratoxin A is a mycotoxin produced by Aspergillus ochraceus and is a natural contaminant of mouldy food. We examined the neuroactive potential of ochratoxin A by measuring the changes in the activities of several membrane bound, cytoplasmic and lysosomal enzymes in the brain of adult female rats, following subchronic application of ochratoxin A. The activities of both soluble and membrane bou...

In order to gain insight into the mechanistic role of a flexible exterior loop near the active site, made up of Y62, H63, G64, and Y65, that has been proposed to play an important role in substrate binding and recognition in the methionyl aminopeptidase from Escherichia coli (EcMetAP-I), the H63A enzyme was prepared. Mutation of H63 to alanine does not affect the ability of the enzyme to bind d...

The ability of synthetic protein fragments to survive the degradative action of aminopeptidases and serum proteolytic enzymes can be remarkably enhanced by slight modifications at their N-terminal alpha-amino group. This can be achieved by addition of beta-alanine or amino acids of the D-configuration, amino acids which are seldom found in a living organism. These modifications do scarcely modi...

OBJECTIVES Changes in the activity of beta-glucuronidase, N-acetyl-beta-glucosaminidase, cathepsin D and L, alanine aminopeptidase and lysosomal acid lipase in lysosomal fractions of the liver and kidneys of mice, which were administered 20 mg/kg b.w. of exogenous melatonin (N-acetyl-5-methoxytryptamine) for 7 and 14 days were investigated. METHODS The slices of the liver and kidney were homo...

Total protein (TP), albumin (Alb), transferrin (TRF), retinol-binding protein (RPB), N-acetyl-beta-glucosaminidase (NAG), alanine aminopeptidase (AAP), gamma-glutamyltransferase (GGT), and creatinine (Cr) were measured in random (untimed) urine samples from 29 nonpregnant women and from pregnant subjects (11 in the first trimester, 34 in the second, and 37 in the third). The excretion of TP, Al...

Jejunal perfusion in the rat with Ringer solution containing 10 mmol/l taurocholate removes considerable quantities of protein and brush border membrane enzymes from the intestinal epithelium. The duration of the experiments was 7.5 h. One group of animals was given 200 micrograms cycloheximide per 100 g body weight intramuscularly 1 h before start of the perfusion. Serial estimations of protei...

The average biological intra-individual CV in 20 patients with chronic liver diseases (CLD), estimated for 14 analytes during a stationary phase, significantly exceeded that for a normal group in the cases of Na+, K+, Cl-, total protein, albumin, cholinesterase, hemoglobin, and alpha-amylase; it did not differ significantly from the normal group for cholesterol, alkaline phosphatase, aspartate ...