Several investigators (Creaser, 1955; Pardee, 1955; Spiegelman et al., 1955; Horowitz et al., 1958) have shown inhibition of enzyme induction by pyrimidine and purine analogues. The inhibition results apparently from interference with nucleic acid synthesis. In experiments with other compounds which might interfere with nucleic acid metabolism, we found a stimulation of enzyme induction in Esch...

In the Reuber (H35) hepatoma cell strain, microsomal aryl hydrocarbon (benzo[a]pyrene) hydroxylase is induced 25-fold by the polycyclic hydrocarbon benz[a]anthracene but is not induced by the steroid hormone dexamethasone. Soluble tyrosine aminotransferase is induced sixfold by dexamethasone and twofold by benz[a]anthracene. Each enzyme requires similar inducer concentrations for induction, and...

Ornithine decarboxylase has been induced in log phase hepatoma cells grown in suspension culture. Induction with N6, O2'-dibutyryl cyclic adenosine 3':5'-monophosphate produced a 4-fold increase in enzyme activity by 3 hours which was followed by a return to base levels by 6 hours. Induction with dexamethasone, a potent synthetic glucocorticoid, exhibited a slow steady rate of increase in enzy...

objective: organophosphorus hydrolase (oph) is a homodimeric enzyme that can hydrolyze phosphoester bonds and reduce the toxicity of organophosphorus compounds. this makes oph a suitable element for the biodegradation of these compounds. methods: we successfully cloned the oph gene from pseudomonas diminuta, after optimization for pichia pastoris, into a yeast expression vector (ppiczαb). afte...

Recombinantly produced enzymes are applied in many fields, ranging from medicine to food and nutrition, production of detergents, textile, leather, paper, pulp, plastics. Thus, the cost-effectiveness recombinant enzyme synthesis is an important issue biotechnological industry. Isopropyl-β-D-thiogalactoside (IPTG), analog lactose, currently most widely used chemical agent for induction synthesis...

Induction of an nicotinamide adenine dinucleotide-specific malic enzyme and a malate entry system permits Streptococcus faecalis to grow at the expense of malate. Evidence is presented which shows that biosynthesis of the permease, but not of the malic enzyme, is subject to catabolite repression by glucose. In contrast to the malic enzyme, the catalytic function of the entry system does not app...

A new non-specific nuclease from Yersinia enterocolitica subsp. palearctica (Y. NSN) was expressed in Escherichia coli (E. coli) BL 21 StarTM (DE3)plysS. Induction conditions, including isopropyl-β-D-thiogalactoside (IPTG) concentration, cell density (OD600), induction time and induction temperature, were optimized using response surface methodology. Statistical analysis of the results revealed...