Isolation, by affinity chromatography, of mutant escherichia coli cells with novel regulation of lamB expression.
نویسندگان
چکیده
Affinity chromatography was used as a positive genetic selection technique for the isolation of cells exhibiting high levels of surface receptor expression. Starting from a large population of Escherichia coli with no maltodextrin receptor due to a deletion of malT, the positive regulator gene required for receptor synthesis, cells were chromatographically enriched that could bind to starch-Sepharose, an immobilized ligand of the receptor. One such isolate showed over 25% of wild-type-induced levels of receptor in the absence of malT and levels higher than that of the wild type in a malT+ background. In contrast to wild-type cells, receptor expression in the isolate was insensitive to control by cAMP. The maltodextrin receptor synthesized by the mutant was identical to wild-type protein in terms of ligand affinity and electrophoretic mobility and was dependent on lamB, the structural gene for the receptor. The directed evolution of this novel form of lamB expression was dependent on at least two mutations in the isolate.
منابع مشابه
Expression of Recombinant Protein B Subunit Pili from Vibrio Cholera
Background & Aims: Vibrio cholerae is a gram-negative bacterial pathogen that causes cholera disease. Following ingestion by a host and entry into the upper intestine, V. cholera colonizes and begins to emit enterotoxin. One of the most pathogenic factors of Vibrio cholera is toxin-coregulated pili (TCP). ToxinCoregulated pili is as the primary factor requiered for the colonization and insisten...
متن کاملPersian sturgeon growth hormone elaboration and purification
In this study Escherichia coli DE3 containing expression vector (pET21a) with cloned Persian sturgeon growth hormone (psGH) gene was grown in 10 mL LB broth on a 150 rpm shaker, at the temperature of 37 °C. At the late log phase (determined by OD standard curve) 100 &muL isopropyl &beta-D-1-thiogalactopyranoside (IPTG) was added for induction of GH synthesis. Samples were taken every 2 hours an...
متن کاملPersian sturgeon growth hormone elaboration and purification
In this study Escherichia coli DE3 containing expression vector (pET21a) with cloned Persian sturgeon growth hormone (psGH) gene was grown in 10 mL LB broth on a 150 rpm shaker, at the temperature of 37 °C. At the late log phase (determined by OD standard curve) 100 &muL isopropyl &beta-D-1-thiogalactopyranoside (IPTG) was added for induction of GH synthesis. Samples were taken every 2 hours an...
متن کاملSoluble Expression and Purification of Q59L Mutant L-asparaginase in the Presence of Chaperones in SHuffle™ T7 strain
Background and Aims: Q59L mutant of L-asparaginase enzyme from Escherichia coli (E. coli) has been introduced with lower side effects. This version of the enzyme might have potential applications in the treatment of leukemia patients. We utilized SHuffle T7 strain of E. coli, to produce the mutant enzyme in the presence of chaperone molecules. Materials and Methods: Q59LAsp gene was cloned in...
متن کاملCloning and evaluation of gene expression and purification of gene encoding recombinant protein containing binding subunit of coli surface antigens CS1 and CS2 from Enterotoxigenic Escherichia coli
Background & Objective: Enterotoxigenic Escherichia coli (ETEC) is a major causative agent of diarrhea. Enterotoxins and the colonization factors (CFs) are major virulence factors in ETEC infections. The bacterium binds to the intestinal epithelial cell surface through colonization factors and produces enterotoxins that cause excessive fluid and electrolyte secretion in the lumen of the intesti...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Journal of bacteriology
دوره 154 2 شماره
صفحات -
تاریخ انتشار 1983