The activity of a purified cytosolic aminopeptidase (Mr 79,000) from monkey brain was stimulated about 4-fold by ATP-Mg2+. The stimulation was seen with either synthetic aminopeptidase substrates or natural peptides such as enkephalins. Both ATP and Mg2+ were required for stimulation, and ADP did not inhibit the stimulation. Non-hydrolysable analogues of ATP, deoxy-ATP and other nucleoside trip...

A continuous procedure for the determination of leucine aminopeptidase is described. L-leucinamide is used as substrate and the liberated ammonia is determined with the glutamate dehydrogenase reaction. The enzyme is Mn2+-activated and 30 mumol/l MnCl2 is necessary for an optimal activity measurement. Influence of buffer type, buffer concentration and pH are reported together with the apparent ...

The property of solutions of Triton X-114 to separate into detergent-rich and detergent-poor phases at 30 degrees C has been exploited to investigate the identities of the aminopeptidases in synaptic membrane preparations from pig striatum. When titrated with an antiserum to aminopeptidase N (EC 3.4.11.2), synaptic membranes solubilized with Triton X-100 revealed that this enzyme apparently com...

This study analyzes the fluorimetric determination of alanyl- (Ala), glutamyl- (Glu), leucyl-cystinyl- (Cys) and aspartyl-aminopeptidase (AspAp) urinary enzymatic activities as early and predictive biomarkers of renal dysfunction in cisplatin-treated rats. Male Wistar rats (n = 8 each group) received a single subcutaneous injection of either saline or cisplatin 3.5 or 7 mg/kg, and urine samples...

the measurement of “alanine aminopeptidase” in urine. J Clin Chem Clin Biochem 1988;26:635-44. 3. Jung K, ScholzD. An optimized assay of alanine aminopeptidase activity in urine. Clin Chem 1980;26:1251-4. 4. Flandrois C, Lahet C, Feldmann D, Gabastou JM, Gonnon A, Maire I. Urinary alanine aminopeptidase assay improved as result of multivariate response-surface analysis. Clin Chem 1988;34:954-7....

Robinson, Birnbaum, and Greenstein (1) in 1953 accomplished the isolation of renal aminopeptidase from fresh hog kidney by extracting the activity from the particulate fraction of kidney homogenate with I-butanol and thereafter fractionating between 50 and 75% saturation with ammonium sulfate at pH 7. About 30% of the final product was extractable by organic solvents, the extractable material a...

In an examination of arginine-utilizing Mycoplasma species, simple fluorogenic and chromogenic tests were used to demonstrate high levels of arginine aminopeptidase activity in unwashed, unconcentrated broth and agar cultures in all strains of 5 species and low levels of activity in all strains of 14 species. Four species contained strains which exhibited either high or low levels of activity.

A rapid colorimetric method for the presumptive identification of group A streptococci and enterococci based upon pyroglutamyl aminopeptidase activity is described. Of 76 group A streptococcal isolates from primary plates, 83 gave positive reactions, and the remaining 7 were positive on retesting in pure culture. Of the 31 enterococcal isolates tested, all gave positive reactions. Despite occas...