An efficient heat-inducible Bacillus subtilis bacteriophage 105 expression and secretion system for the production of the Streptomyces clavuligerus beta-lactamase inhibitory protein (BLIP).
The Streptomyces clavuligerus beta-lactamase inhibitory protein (BLIP) has been shown to be a potent inhibitor of class A beta-lactamases including the Escherichia coli TEM-1 beta-lactamase (Ki = 0.6 nM). A heat-inducible BLIP expression system was constructed based on a derivative of Bacillus subtilis phage phi105. The recombinant BLIP produced by this system was secreted to the culture medium, purified to homogeneity, and fully active. We have shown that the signal peptide of BLIP functions well in B. subtilis to secrete BLIP out of the cells, which facilitates purification. The absence of a His-tag also avoids the activity and structure of BLIP being altered. An unprecedented high yield of recoverable protein in culture supernatant (3.6mg of >95% pure BLIP/l culture) was achieved by a simple purification protocol. We have developed an efficient production process in which the culture time before heat-induction was 3-4h and the culture supernatant could be collected 5h after induction. This total time of 8-9h is considered to be very short compared to that of the native S. clavuligerus culturing (60-70h). We achieved a very efficient BLIP production rate of 0.8-0.9mg/l/h. Heterologous gene expression was tightly controlled and no production of BLIP was observed before heat-induction, suggesting that cell density can be further increased to improve enzyme yield.
Liu
Hong-Bing
HB
The Central Laboratory of the Institute of Molecular Technology for Drug Discovery and Synthesis and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
Chui
Ka-Shun
KS
Chan
Chi-Leong
CL
Tsang
Chun-Wai
CW
Leung
Yun-Chung
YC
D017103:Bacillus Phages / Q000201:enzymology* / Q000235:genetics*; D001412:Bacillus subtilis / Q000821:virology; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D004789:Enzyme Activation; D006358:Hot Temperature; D007700:Kinetics; D008970:Molecular Weight; D015202:Protein Engineering / Q000379:methods*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D013045:Species Specificity; D013302:Streptomyces / Q000145:classification / Q000201:enzymology* / Q000235:genetics*; D013379:Substrate Specificity; D065093:beta-Lactamase Inhibitors
D001426:Bacterial Proteins; D011994:Recombinant Proteins; D065093:beta-Lactamase Inhibitors; C065596:beta-lactamase-inhibitor protein, Streptomyces