Proline-specific extracellular aminopeptidase purified from Streptomyces lavendulae

Appl Biochem Biotechnol. 2011 Apr;163(8):994-1001. doi: 10.1007/s12010-010-9103-0. Epub 2010 Oct 13.

Abstract

Aminopeptidases catalyze the cleavage of specific amino acids from the amino terminus of protein or peptide substrates. A proline-specific aminopeptidase was purified to homogeneity from the culture-free extract of Streptomyces lavendulae ATCC 14162 in sequential steps comprising ammonium sulfate precipitation, ultra-filtration, and column chromatography on Q-sepharose and Sephadex G-100. The purified protein showed approximately 60 kDa in SDS-PAGE and was optimally active at pH 6.5 and 40 °C. Kinetic studies showed a K(m) and V(max) of 0.23 mM and 0.087 μmol/min, respectively, using Pro-p-NA, the substrate with maximum specificity. Enzyme activity was inhibited by PMSF and ions like Zn²+, Co²+, and Ni²+. However, unlike other aminopeptidases, the activity was enhanced in the presence of DTT, 1,10-phenanthroline, EDTA, amastatin, and bestatin. Ions like Ca²+, Mg²+, and Mn²+ also enhanced the activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminopeptidases / chemistry*
  • Aminopeptidases / isolation & purification*
  • Aminopeptidases / metabolism
  • Chromatography
  • Enzyme Stability
  • Filtration
  • Fungal Proteins / chemistry*
  • Fungal Proteins / isolation & purification*
  • Fungal Proteins / metabolism
  • Kinetics
  • Proline / metabolism*
  • Streptomyces / chemistry
  • Streptomyces / enzymology*
  • Substrate Specificity

Substances

  • Fungal Proteins
  • Proline
  • Aminopeptidases