PMID: 14626424Nov 25, 2003

Expression and characterization of Kluyveromyces lactis beta-galactosidase in Escherichia coli

Biotechnology Letters
C S KimDeok-Kun Oh


Kluyveromyces lactis beta-galactosidase gene, LAC4, was expressed in Escherichia coli as a soluble His-tagged recombinant enzyme under the optimized culture conditions. The expressed protein was multimeric with a subunit molecular mass of 118 kDa. The dimeric form of the beta-galactosidase was the major fraction but had a lower activity than those of the multimeric forms. The purified enzyme required Mn2+ for activity and was inactivated irreversibly by imidazole above 50 mM. The activity was optimal at 37 and 40 degrees C for o-nitrophenyl-beta-D-galactopyranoside (oNPG) and lactose, respectively. The optimum pH value is 7. The Km and Vmax values of the purified enzyme for oNPG were 1.5 mM and 560 micromol min(-1) mg(-1), and for lactose 20 mM and 570 micromol min(-1) mg(-1), respectively.


Aug 27, 2004·Biotechnology and Bioengineering·R SchoevaartR A Sheldon
Oct 14, 2004·Journal of Applied Microbiology·C S KimD-K Oh
Jan 1, 2013·Applied Biochemistry and Biotechnology·Andrew N W BellDavid J Timson
Aug 1, 2020·International Journal of Molecular Sciences·Maria RutkiewiczAnna Bujacz
Nov 28, 2009·Applied Microbiology and Biotechnology·Ah-Reum Park, Deok-Kun Oh
Sep 30, 2005·Applied Microbiology and Biotechnology·Hans P SørensenMads G Johnsen

Related Concepts

Gene Expression Regulation, Bacterial
Alkalescens-Dispar Group
Gene Expression Regulation, Enzymologic
2-nitrophenylgalactoside, (beta-D)-isomer

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