Cloning of poly(aspartic acid) (PAA) hydrolase-1 gene from Pedobacter sp. KP-2 and hydrolysis of thermally synthesized PAA by its gene product

Macromol Biosci. 2009 Jan 9;9(1):10-9. doi: 10.1002/mabi.200800106.

Abstract

Pedobacter sp. KP-2 can degrade and metabolize thermally synthesized alpha,beta-poly(D,L-aspartic acid) (tPAA), which contains 70% of unnatural beta-amide units, with high-molecular-weight. In this study, gene cloning and molecular characterization of PAA hydrolase-1 from KP-2 was carried out. Gene analysis reveals that deduced amino acid sequence of the enzyme shows a similarity to only that of PAA hydrolase-1 from Sphingomonas sp. KT-1. GPC and NMR analyses of the hydrolyzed products of tPAA by PAA hydrolase-1 of KP-2 indicate that this enzyme cleaves the beta-beta amide linkage via endo-mode to yield oligo(aspartic acid) from tPAA. Taking the composition of tPAA and the substrate specificity of PAA hydrolase-1 into consideration, the enzyme possibly plays a crucial role in tPAA biodegradation by KP-2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins* / genetics
  • Bacterial Proteins* / metabolism
  • Cloning, Molecular
  • Gram-Negative Bacteria / enzymology*
  • Hydrolases* / genetics
  • Hydrolases* / metabolism
  • Molecular Sequence Data
  • Molecular Structure
  • Mutagenesis, Site-Directed
  • Peptides* / chemical synthesis
  • Peptides* / metabolism
  • Sequence Alignment

Substances

  • Bacterial Proteins
  • Peptides
  • polyaspartate
  • Hydrolases