Characterization of Cyclodextrin Glycosyltransferase of the Same Gene Expressed from Bacillus macerans, Bacillus subtilis, and Escherichia coli

Abstract

The plasmid pHG contains a cyclodextrin glycosyltransferase (CGTase) gene (cgt) derived from Bacillus macerans. Two transformants, Bacillus subtilis (pHG) and Escherichia coli (pHG), were found to produce CGTases with the same primary structure as the enzyme from B. macerans. However, the beta-cyclodextrin coupling activity of the CGTase from E. coli (pHG) was 14-fold higher than that of the enzymes from the other strains. By contrast, no differences in alpha-cyclodextrin coupling activities were observed among these CGTases. CGTase from E. coli (pHG) was found to be less thermostable than the other CGTases. When the CGTase produced by B. subtilis was treated with increasing urea concentrations (10-1000 mM) to promote increasing degrees of protein unfolding, a bell-shaped beta-cyclodextrin coupling activity profile was obtained. Subtle differences in the conformation of the CGTase produced by E. coli are therefore proposed to be responsible for the markedly increased beta-cyclodextrin coupling activity of this enzyme.

Retracted: Antimicrobial action of chemically modified cotton fabric with cyclodextrin

“…1 They are torodialshaped cyclic oligosaccharides with a hydrophilic outer surface and an internal hydrophobic hollow…”

Improved activity of β-cyclodextrin glycosyltransferase from Bacillus sp. N-227 via mutagenesis of the conserved residues

“…The standard CGTase activity assays described above was used to determine the residual activity of each enzyme (Jeang et al 2005). …”

Optimization of culture media for extracellular expression of streptokinase in Escherichia coli using response surface methodology in combination with Plackett-Burman Design

“…Although heterologous expression in E. coli could bring about numerous advantages, accumulation of the expressed protein in the cytosol as a biologically inactive protein aggregate (inclusion body) is a significant problem that could be overcame by extracellular expression (periplasmic space or culture medium) of recombinant protein [5,6]. However, recombinant proteins most often fail to translocate across the inner and outer membranes of E. coli cells [7,8].…”