Heat-Shock and Stringent Responses Have Overlapping Protease Activity in Escherichia coli: Implications for Heterologous Protein Yield

1999 ◽  
Vol 80 (1) ◽  
pp. 23-38 ◽  
Author(s):  
Sarah W. Harcum ◽  
William E. Bentley
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Protease Activity ◽  
Heterologous Protein ◽  
Protein Yield

scholarly journals Roles of DegP in Prevention of Protein Misfolding in the Periplasm upon Overexpression of Penicillin Acylase in Escherichia coli

2003 ◽  
Vol 185 (10) ◽  
pp. 3020-3030 ◽  
Author(s):  
Kao-Lu Pan ◽  
Hsu-Chou Hsiao ◽  
Chiao-Ling Weng ◽  
Ming-Sheng Wu ◽  
C. Perry Chou
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Protease Activity ◽  
Protein Misfolding ◽  
Inclusion Bodies ◽  
Penicillin Acylase ◽  
Chaperone Activity ◽  
Culture Performance

ABSTRACT Enhancement of the production of soluble recombinant penicillin acylase in Escherichia coli via coexpression of a periplasmic protease/chaperone, DegP, was demonstrated. Coexpression of DegP resulted in a shift of in vivo penicillin acylase (PAC) synthesis flux from the nonproductive pathway to the productive one when pac was overexpressed. The number of inclusion bodies, which consist primarily of protein aggregates of PAC precursors in the periplasm, was highly reduced, and the specific PAC activity was highly increased. DegP was a heat shock protein induced in response to pac overexpression, suggesting that the protein could possibly suppress the physiological toxicity caused by pac overexpression. Coexpression of DegPS210A, a DegP mutant without protease activity but retaining chaperone activity, could not suppress the physiological toxicity, suggesting that DegP protease activity was primarily responsible for the suppression, possibly by degradation of abnormal proteins when pac was overexpressed. However, a shortage of periplasmic protease activity was not the only reason for the deterioration in culture performance upon pac overexpression because coexpression of a DegP-homologous periplasmic protease, DegQ or DegS, could not suppress the physiological toxicity. The chaperone activity of DegP is proposed to be another possible factor contributing to the suppression.

Expression and characterization of an α-glucosidase from Thermoanaerobacter ethanolicus JW200 with potential for industrial application

Biologia ◽  
2009 ◽  
Vol 64 (6) ◽  
Author(s):  
Yue-Hong Wang ◽  
Yu Jiang ◽  
Zuo-Ying Duan ◽  
Wei-Lan Shao ◽  
Hua-Zhong Li
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Optimal Condition ◽  
Industrial Application ◽  
Conversion Rate ◽  
Hydrolytic Activity ◽  
Thermoanaerobacter Ethanolicus ◽  
Transglycosylation Activity

AbstractIn this study, a new α-glucosidase gene from Thermoanaerobacter ethanolicus JW200 was cloned and expressed in Escherichia coli by a novel heat-shock vector pHsh. The recombinant α-glucosidase exhibited its maximum hydrolytic activity at 70°C and pH 5.0∼5.5. With p-nitrophenyl-α-D-glucoside as a substrate and under the optimal condition (70°C, pH 5.5), K m and V max of the enzyme was 1.72 mM and 39 U/mg, respectively. The purified α-glucosidase could hydrolyze oligosaccharides with both α-1,4 and α-1,6 linkages. The enzyme also had strong transglycosylation activity when maltose was used as sugar donor. The transglucosylation products towards maltose are isomaltose, maltotriose, panose, isomaltotriose and tetrasaccharides. The enzyme could convert 400 g/L maltose to oligosaccharides with a conversion rate of 52%, and 83% of the oligosaccharides formed were prebiotic isomaltooligosaccharides (containing isomaltose, panose and isomaltotriose).

scholarly journals Sequence of the lon gene in Escherichia coli. A heat-shock gene which encodes the ATP-dependent protease La.

1988 ◽  
Vol 263 (24) ◽  
pp. 11718-11728 ◽  
Author(s):  
D T Chin ◽  
S A Goff ◽  
T Webster ◽  
T Smith ◽  
A L Goldberg
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Heat Shock Gene ◽  
Shock Gene
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