Aminopeptidase Activity

RE Stratford Jr, VHL Lee. (1985). Aminopeptidase activity in albino rabbit extraocular tissues relative to the small intestine. J Pharm Sci 74 731-734. 

Harnett, W., Houston, K.M., Tate, R., Garate, T., Apfel, H., Adam, R., Haslam, S.M., Panico, M., Paxton, T., Dell, A., Morris, H. and Brzeski, H. (1999b) Molecular cloning and demonstration of an aminopeptidase activity in a filarial nematode glycoprotein. Molecular and Biochemical Parasitology 104,11—23. 

Bestatin (ubenimex) is a potent inhibitor of aminopeptidase N and aminopeptidase B,89 which was isolated from a culture filtrate of Streptomyces olivoreticuli during the search for specific inhibitors of enzymes present on the membrane of eukaryotic cells.90 Inhibitors of aminopeptidase activity are associated with macrophage activation and differentiation, Bestatin has shown significant therapeutic effects in several clinical trials.91 In a multi-institutional study,92 patients with acute non-lymphocytic leukemia (ANLL) were randomized to receive either Bestatin or placebo orally after completion of induction and consolidation therapy, and concomitant with maintenance chemotherapy. Remission duration was prolonged in the Bestatin group, although this difference did... 

Aoyagi, T. et al., Aminopeptidase activities on the surface of mammalian cells, Biochimica Et Biophysica Acta, 452, 131, 1976. 

A recent study, however, has shown that aminopeptidase activity is present on the surface of porcine buccal mucosa, and that various aminopeptidase inhibitors, including amastatin and sodium deoxycholate, reduce the mucosal surface degradation of the aminopeptidase substrate, leucine-enkephalin [149], Since the peptidases are present on the surface of the buccal mucosa, they may act as a significant barrier to the permeability of compounds which are substrates for the enzyme. In addition to proteolytic enzymes, there exist some esterases, oxidases, and reductases originating from buccal epithelial cells, as well as phosphatases and carbohydrases present in saliva [154], all of which may potentially be involved in the metabolism of topically applied compounds. 

Ohkubo K, Baraniuk JN, Hohman R, Merida M, Hersh LB, Kaliner MA (1998) Aminopeptidase activity in human nasal mucosa. J Allergy Clin Immunol 102 741-750. 

Stratford RE, and Lee VHL (1986) Aminopeptidase activity in homogenates of various absorptive mucosae in the albino rabbit Implications in peptide delivery. Int. J. Pharm. 30 73-82. 

Preliminary information useful in prodrug design has been obtained with amino acids attached to model aromatic amines. Thus, N-(naphthalen-2-yl) amides of amino acids (6.1, R=side chain of amino acid, R =H) proved to be of interest as test compounds to monitor peptidase activity such as ami-nopeptidase M (membrane alanyl aminopeptidase, microsomal aminopepti-dase, EC 3.4.11.2) [16][17], In the presence of purified rabbit kidney aminopeptidase M or human cerebrospinal fluid (CSF) aminopeptidase activity, the rate of hydrolysis decreased in the order Ala-> Leu->Arg->Glu-2-naphthyl-amide. Ala-2-naphthylamide, in particular, proved to be a good test compound, as its rate of hydrolysis was influenced by experimental conditions (preparation, inhibitors, etc.), as was the hydrolysis of a number of low-molecular-weight opioid peptides and circulating vasoactive peptides. 

Larmas M, Makinen KK and Scheinin A (1968) Histochemical studies on the aryl-aminopeptidase activity in human carious dentine. Acta Odontol Scand 26,127-136. 

This mammalian lysosomal endopeptidase [EC 3.4.22.16] is also known as aleurain, cathepsin B3, cathepsin BA, and benzoylarginineinaphthylamide hydrolase. A member of the peptidase family Cl, the enzyme also acts with an aminopeptidase activity, preferring Arg— Xaa peptide bonds. 

CN164 Arechaga, G., I. Prieto, A. B. Segarra, et al. Dietary fatty acid composition affects aminopeptidase activities in the testes of mice. Int J Androl 2002 25(2) 113-118. 

Lactic streptococci initiate casein degradation through the action of cell wall-associated and cell membrane-associated proteinases and peptidases. Small peptides are taken into the cell and hydrolyzed to their constituent amino acids by intracellular peptidases (Law and Sharpe 1978). Peptides containing four to seven residues can be transported into the cell by S. cremoris (Law et al. 1976B). S. lactis and S. cremoris have surface-bound peptidases and thus are not totally dependent on peptide uptake for protein use (Law 1979B). Some surface peptidases of S. cremoris are located in the cell membrane, whereas others are located at the cell wall-cell membrane interface (Exterkate 1984). Lactic streptococci have at least six different aminopeptidase activities, and can be divided into three groups based on their aminopeptidase profiles (Kaminogawa et al 1984). 

Tavakoli-Saberi, M.R., A. Williams, and K.L. Audus. 1991. Aminopeptidase activity in human buccal epithelium and primary cultures of hamster buccal epithelium. Pharm Res 6 S197. 

To stabilize the tetrapeptide to aminopeptidase activity, amide bonds were reduced to the corresponding amines. A key observation was that modification of some of these peptide bonds negated the ability of a compound to serve as a substrate unlike before, this was independent of the identity of the a amino acids. While the peptide CllhS la was a good substrate for FTase, reduction of the first two amide bonds (cysteine, and aj-isoleucine) produced compound Id which was a potent inhibitor (IC50 20 nM) but was not a substrate (Table 2).33 Reduction of only one amide bond to give compounds lb and lc was also well tolerated in terms of inhibition potency, but both compounds were now substrates for FTase. This... 

Jacobsen, T. R., and H. Rai. 1991. Aminopeptidase activity in lakes of differing eutrophication. In Microbial Enzymes in Aquatic Ecosystems (R. J. Chrost Ed.), pp. 144-164, Springer-Verlag, New York. 

Stepanauskas, R., H. Edling, and L. J. Tranvik. 1999. Differential dissolved organic nitrogen availability and bacterial aminopeptidase activity in limnic and marine waters. Microbial Ecology 38 264-272. 

Thompson, A., and R. L. Sinsabaugh. 2000. Matric and particulate phosphatase and leucine aminopeptidase activity in limnetic biofilms. Aquatic Microbial Ecology 2 151-159. 

An aminopeptidase activity has been demonstrated to cleave the N-terminal Arg residue from bovine /3-lipotropin [49]. This activity appears to be specific for basic residues, but is blocked by the presence of proline residues on the carboxyl side of the N-terminal arginine [22]. However, it is not yet clear whether this aminopeptidase is involved in precursor processing in situ. 

Digestion studies using homogenates of kidneys, intestine, and liver indicated a close relationship between the levels of aminopeptidase activity as measured with a specific synthetic substrate and that based on the enzymatic activity responsible for hydrolyzing the isopeptide bond (see Table V). Purified aminopeptidase N from the intestinal brush border of rabbit (68) and pig (64) hydrolyzed a dipeptide and the related isodipeptide with about the same efficiency (see Table VI). These results may explain the findings that methionine covalently bound... 

N Strater, WN Lipscomb (1995) Two-metal ion mechanism of bovine lens leucine aminopeptidase active site solvent structure and binding mode of L-leucinal, a gem-diolate transition state analogue, by X-ray crystallography, Biochemistry 34 14792-14800... 

Application and Principle This procedure is used to determine leucine aminopeptidase activity in enzyme preparations derived from Lactococcus lactis. The assay is based on the rate of absorbance change over 5 min at 30° the change in absorbance is due to liberatedp-nitroaniline from the hydrolysis of leucine p-nitroanilide. 

Sample Solution Prepare a solution in pH 7.0 Phosphate Buffer that contains between 0.025 and 0.1 unit of aminopeptidase activity per mL. 

Calculation One aminopeptidase activity unit (AP) is defined as the quantity of aminopeptidase required to liberate 1 p.inol/min of leucine from leucine p-nitroanilide under the conditions of the assay at pH 7.0 and 30°. 

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