ISSN:
1617-4623
Keywords:
α-Glucosidase
;
Active expression
;
Escherichia coli
;
Refractile bodies
;
Protein folding
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Using standard growth conditions (LB medium, 37°C, induction with 5 mM IPTG) yeast α-glucosidase PI expressed under the control of the regulated tac-hybrid promoter results in the synthesis of insoluble aggregated α-glucosidase granules in Escherichia coli. Under these conditions active soluble α-glucosidase amounts to less than 1% of the heterologously produced protein. However, the amount of soluble active α-glucosidase was dramatically increased when the strong tac-hybrid promoter was to a limited extent induced. This was achieved at concentrations of 0.01 mM IPTG or of 1% lactose or lower in a lactosepermease deficient host strain containing the lacI qrepressor gene on an R-plasmid. The formation of active soluble α-glucosidase was almost 100% when E. coli cells induced in this manner were cultivated under conditions that reduced growth rate, i.e. at decreased temperature, extreme pH values or in minimal and complete media supplemented with different carbon sources.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00332244
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