A novel aminopeptidase fromBurkholderia cepaciaspecific for acidic amino acids

Abstract

An aminopeptidase specific for the N-terminal acidic residue (BcepAP) was purified from the cell extract of Burkholderia cepacia svr as a homotrimeric (subunit mass 66 kDa) molecule. It was identified as an unassigned peptidase of family M61. The only other member characterized so far from this family is a broad-specificity aminopeptidase of Sphingomonas capsulata (ScapAP) with preference for Gly or Ala residues. However, BcepAP exhibited narrow specificity and the preferred substrate was a peptide with an N-terminal Asp or Glu residue, which is quite unusual. The proteins assigned to this family were grouped separately on the basis of their homology to either BcepAP or ScapAP. It led the conclusion that BcepAP is a prototype of a new PepM61 subfamily, with a representative in other Proteobacteria, and to the prediction that members of the family share the ability to cleave N-terminal acidic residues of peptide substrates.

Proteomic and metabolomic analysis of the cellular biomarkers related to inhibitors tolerance in Zymomonas mobilis ZM4

“…Similarly, ZMO1593 was also down-regulated under the ethanol stress [ 10 ]. It is known that bacterial peptidases are involved in protein maturation, metabolism of peptides, and turnover of intracellular proteins, although little has thus far been known about their intrinsic functions [ 56 , 57 ]. However, it implies that these peptidases are, perhaps, important in response to the present inhibitors.…”

“…Previously, Peptidase ZMO1593 was also found to be down-regulated under ethanol stress [ 10 ]. It is known that bacterial peptidases lay physiological functions not only in generalized protein degradation but also in protein maturation, metabolism of peptides, and turnover of intracellular proteins; however, little is known about their specific functions [ 56 , 57 ], especially the function on stress response.…”

Purification and characterization of proline aminopeptidase from chicken intestine

“…The assay mixture (200 l) containing peptide substrates was incubated with purified enzyme (147 U/mg) and buffer (0.1 M sodium phosphate buffer, pH 7.5) at 45 • C and the aliquot (10 l) was removed at 0 min, 5 min, 10 min and 15 min interval. The degradation of these peptides was estimated quantitatively by Ninhydrin method [18]. One unit of enzyme activity is defined as the amount of enzyme that hydrolyzes 1 mol of amino acid residue/min under the given assay conditions.…”

Catalytic triad heterogeneity in S51 peptidase family: Structural basis for functional variability

“…For PepEdr, activity of the enzyme was initially tested using 10‐30 μg enzyme with various substrates (Table S1) at pH 7‐8 and temperature 30‐35°C. Activity toward X‐β‐naphthylamide substrates (X‐βNA; where X is any amino acid) was tested as described by Jamdar . Activity toward other peptide substrates were tested using a modified Ninhydrin assay as described by Yadav et al Activity toward chromogenic peptides (with p‐nitroanilide, pNA) and chromogenic esters (with p‐nitrophenyl, pnp) were tested by incubating with substrates at assay conditions for 10 minutes and measuring absorbance at 410 nm or 405 nm, respectively.…”