These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Overexpression, one-step purification, and biochemical characterization of a recombinant gamma-glutamyltranspeptidase from Bacillus licheniformis.
    Author: Lin LL, Chou PR, Hua YW, Hsu WH.
    Journal: Appl Microbiol Biotechnol; 2006 Nov; 73(1):103-12. PubMed ID: 16850301.
    Abstract:
    A truncated gene from Bacillus lichenifromis ATCC 27811 encoding a recombinant gamma-glutamyltranspeptidase (BLrGGT) was cloned into pQE-30 to generate pQE-BLGGT, and the overexpressed enzyme was purified from the crude extract of IPTG-induced E. coli M15 (pQE-BLGGT) to homogeneity by nickel-chelate chromatography. This protocol yielded over 25 mg of purified BLrGGT per liter of growth culture under optimum conditions. The molecular masses of the subunits of the purified enzyme were determined to be 41 and 22 kDa, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The optimum pH and temperature for the recombinant enzyme were 6-8 and 40 degrees C, respectively. The chloride salt of metal ions Mg(2+), K(+), and Na(+) can activate BLrGGT, whereas that of Pb(2+) dramatically inhibited it. The substrate specificity study showed that L-gamma-glutamyl-p-nitroanilide (L-gamma-Glu-p-NA) is a preference for the enzyme. Steady-state kinetic study revealed that BLrGGT has a k (cat) of 105 s(-1) and a K (m) of 21 microM when using L-gamma-Glu-p-NA as the substrate. With this overexpression and purification system, BLrGGT can now be obtained in quantities necessary for structural characterization and synthesis of commercially important gamma-glutamyl compounds.
    [Abstract] [Full Text] [Related] [New Search]