Journal of Biotechnology 2007-02-01

Characterization of a bifunctional aminoacylase/carboxypeptidase from radioresistant bacterium Deinococcus radiodurans R1.

Long-Liu Lin, Mei-Hua Chen, Hung-Chien Roger Chien, Shu-Chen Kan, Chun-Chang Chen, Hui-Yu Hu, Wen-Hwei Hsu

文献索引:J. Biotechnol. 128 , 322-334, (2007)

全文:HTML全文

摘要

The gene encoding a Deinococcus radiodurans R1 bifunctional aminoacylase/carboxypeptidase (DR_ACY/CP) was amplified by polymerase chain reaction and cloned into pQE-30 to generate pQE-DRAC. The cloned gene consists of an open reading frame of 1197 bp encoding a protein with a molecular mass of 42,729 Da. The predicted amino acid sequence shows high homology with those of Geobacillus kaustophilus aminoacylase, Geobacillus stearothermophilus aminoacylase, Pyrococcus horikoshii carboxypeptidase/aminoacylase and Thermoanaerobacter tengcongensis aminoacylase/carboxypeptidase. The expressed enzyme was purified from the crude extract of IPTG-induced Escherichia coli M15 (pQE-DRAC) to homogeneity by nickel-chelate chromatography. The molecular mass of the purified enzyme was determined to be 43kDa by SDS-PAGE. Maximal aminoacylase activity with N-acetyl-methionine as the substrate occurred at pH 8.0 and 40 degrees C in the sodium phosphate buffer. The aminoacylase activity was strongly inhibited by metal-chelating agents, and was largely restored by divalent cations, such as Co(2+), Mn(2+) and Ni(2+). The purified enzyme had broad specificity toward N-acetylated L-amino acids as well as N-CBZ-peptides. Carboxypeptidase activity of DR_ACY/CP to N-CBZ-Gly-Ala exhibited K(m) and k(cat) values of 4.3mM and 28s(-1), respectively. The enzyme also had activity toward the cell wall-related substrates, D-Ala-Gly, D-Ala-Gly-Gly and L-Orn-L-Ala.


相关化合物

  • Z-ILE-ILE-OH
  • Z-ILE-LEU-OH
  • Z-PHE-LEU-OH

相关文献:

Amphipathic property of free thiol group contributes to an increase in the catalytic efficiency of carboxypeptidase Y.

2002-07-01

[Eur. J. Biochem. 269 , 3220-3225, (2002)]

Debittering effect of Actinomucor elegans peptidases on soybean protein hydrolysates.

2008-01-01

[J. Ind. Microbiol. Biotechnol. 35 , 41-47, (2008)]

Cathepsin A-like activity is possibly the main acidic carboxypeptidase in human platelets.

1997-01-01

[Platelets 8 , 355-360, (1997)]

更多文献...