Aminopeptidase N from Escherichia coli is a broad specificity zinc exopeptidase belonging to aminopeptidase clan MA, family M1. The structures of the ligand-free form and the enzyme-bestatin complex were determined at 1.5- and 1.6-A resolution, respectively. The enzyme is composed of four domains: an N-terminal beta-domain (Met(1)-Asp(193)), a catalytic domain (Phe(194)-Gly(444)), a middle beta...

A series of novel pyrrolidine derivatives was designed, synthesized, and assayed to determine the derivatives' activity against matrix metalloproteinase-2 (MMP-2) and aminopeptidase N (APN)/CD13. Preliminary biological tests showed that most compounds inhibit MMP-2 in a highly selective manner compared to APN. Compounds 9d, 9e, and 9g had better inhibitory activity than LY52 and could be used a...

We localized the methionine aminopeptidase (map) gene on the Escherichia coli chromosome next to the rpsB gene at min 4. Genetically modified strains with the chromosomal map gene under lac promoter control grew only in the presence of the lac operon inducer isopropyl-beta-thiogalactoside. Thus, methionine aminopeptidase is essential for cell growth.

Phosphate shows a non-competitive inhibition toward a Streptomyces aminopeptidase (sAP) between pH 5.85 (Ki = 0.48 mM) and 9.0 (110 mM), with a pKa of 7.1 likely due to ionization of H2PO4-. This non-competitive inhibition pattern indicates that phosphate binding to sAP in solution is different from that in the crystal structure, where phosphate is bound to the active site Zn(II) ions. Fluoride...

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...

Amino acid residues in the metal-binding and putative substrate-binding sites of Escherichia coli methionine aminopeptidase (MAP) were mutated, and their effects on the function of the enzyme were investigated. Substitution of any amino acid residue at the metal-binding site resulted in complete loss of the two cobalt ions bound to the protein and diminished the enzyme activity. However, only C...

Aim: To compare diagnostic values and laboratory variables of alanine aminopeptidase (microsomale AAP), γ-glutamyl transferase (γGT), β2-microglobuline (β2-M), C Reactive Protein (CRP) and index for disease activity (PASI) in early diagnosis in previously untreated Psoriatic arthritis (Psa). To determine the effect of untreated Psoriatic arthritis on tubular function, sensitivity of the Brush B...

Thirteen newborn infants, 8 term and 5 preterm (gestational age 31 to 36 weeks), were treated for between 3 and 7 days with gentamicin and ampicillin or cloxacillin because of suspected bacterial infection. The dosage of gentamicin was carefully monitored by serum concentration assays. Urinary alanine aminopeptidase, urinary beta 2-microglobulin, serum urea, and serum beta 2-microglobulin were ...

OBJECTIVES The aim of our study was to evaluate urinary excretion of three brush border enzymes: gamma-glutamyl transferase, alanine aminopeptidase, and leucyl aminopeptidase in pregnant women with various types of hypertensive disorders. MATERIAL AND METHODS The study included 120 pregnant women, further subdivided into four groups: 41 women at ≥ 20 weeks gestation with gestational hypertens...