Disease relevance of L-Leucyl-p-nitroanilide

• Using a sensitive biochemical assay with L-leucyl-p-nitroanilide as a substrate we demonstrated that in vitro melanoma cells also exhibit LAP activity [1].

High impact information on L-Leucyl-p-nitroanilide

• The kinetic constants for each enzyme against L-leucine-p-nitroanilide do not change significantly after acetylation [2].
• The hydrolysis of L-leucine-p-nitroanilide was measured spectrophotometrically in triplicate between 25 and 85 degrees C at eight substrate concentrations ranging from 5 to 800 microM [3].
• The method is based on the enzymatic release of p-nitroaniline (PNA) from two specific synthetic oxytocinase substrates, S-benzyl-L-cysteine-p-nitroanilide (BCN) and L-leucine-p-nitroanilide (LN), respectively [4].
• L-Leucine-p-nitroanilide is by far the most susceptible of the three substrates, and the hyperactivation previously observed with aminopeptidase containing either Ni2+ or Cu2+ in the first binding site and Zn2+ in the second site occurs only with the two poorer substrates, L-alanine-p-nitroanilide and L-valine-p-nitroanilide [5].
• Human skeletal muscle homogenate has been shown to contain enzymes that catalyze the hydrolysis of L-leucyl p-nitroanilide and carbobenzoxyglutamyl-L-tyrosine, known substrates, respectively, for arylamidase and cathepsin A [6].

Biological context of L-Leucyl-p-nitroanilide

• Oxytocinase (EC 3.4.11.3) activity in amniotic fluid samples obtained from 200 normal pregnant women (mean age, 28 years) between 14 and 40 weeks of gestation and during active labor was assayed using S-benzyl-L-cysteine-p-nitroanilide (BCN) and L-leucine-p-nitroanilide (LN) separately as substrates [7].
• Six exopeptidases present in human diploid fibroblasts were identified by separation on polyacrylamide gel electrophoresis and their activity profiles against 17 dipeptides, two tripeptides and L-leucine-p-nitroanilide determined [8].

Anatomical context of L-Leucyl-p-nitroanilide

• We present evidence for the presence of endogenous cystinyl aminopeptidase in membranes from Chinese hamster ovary (CHO-K1) cells by binding studies with [125I]Ang IV and by measuring the cleavage of L-leucine-p-nitroanilide [9].
• Two isoenzymes of oxytocinase activity were fractionated from human seminal plasma by acrylamide-agarose gel chromatography and partly characterized using S-benzyl-L-cysteine-p-nitroanilide (BCN) and L-leucine-p-nitroanilide (LN) separately as substrates [10].
• An L-leucine aminopeptidase (alpha-aminoacyl-peptide hydrolase (cytosol), EC 3.4.11.1), having a specificity toward the substrate L-leucine amide, but not toward L-leucyl beta-naphthylamide or L-leucyl p-nitroanilide, has been purified 332-fold from swine liver, with a yield of 8.6% [11].

Associations of L-Leucyl-p-nitroanilide with other chemical compounds

• One specifically hydrolysed N-alpha-benzoyl-DL-arginine-4-nitroanilide and was termed endopeptidase and the other hydrolysed L-lysine- and L-leucine-4-nitroanilide and was termed aminopeptidase [12].

Gene context of L-Leucyl-p-nitroanilide

• Ten of the M. salivarium and 8 of the M. orale strains were tested for aminopeptidase activity as well, using L-leucine-p-nitroanilide as a substrate, and were shown to possess the activity [13].
• The Km of APM on rat brain membranes for L-Leucine-p-nitroanilide (0.383 mM) was similar to the Km of purified porcine kidney APM (0.558 mM) [14].
• 2. The purified enzyme was most active at pH 8.0 with L-leucine-p-nitroanilide as substrate; the Km value for this substrate was 1.1 mmol/l. The microsomal PAP was immunologically different from the pregnancy serum cystyl aminopeptidase (serum PAP) [15].

References