Burkholderia (formerly Pseudomonas) cepacia AC1100 mineralizes the herbicide 2,4,5-trichlorophenoxyacetate (2,4,5-T), and the first intermediate of 2,4,5-T degradation is 2,4,5-trichlorophenol. Chlorophenol 4-monooxygenase activity responsible for 2,4,5-trichlorophenol degradation was detected in the cell extract. The enzyme consisted of two components separated during purification, and both we...

Mouse thymidylate synthase R209K (a mutation corresponding to R218K in Lactobacillus casei), overexpressed in thymidylate synthase-deficient Escherichia coli strain, was poorly soluble and with only feeble enzyme activity. The mutated protein, incubated with FdUMP and N(5,10)-methylenetetrahydrofolate, did not form a complex stable under conditions of SDS/polyacrylamide gel electrophoresis. The...

-Gelation and precipitation are two possible outcomes for the polymerization of monomers dissolved in a solvent. Gelation is obtained when the polymers

in this paper, polyacrylamide/chromium acetate gel polymer system was prepared as water shut-off system to control water production in one of the iranian oil reservoirs condition. effect of various parameters such as temperature (90 °c) and water formation from view point of salinity and divalent cations, was evaluated on the gelation kinetic and gel strength using bottle testing method. the re...

Nachmansohn and Machado (1) discovered a soluble enzyme system in extracts of brain tissue which catalyzed the formation of active acetate in the presence of ATPI and CoA. Active acetate was detected by the acetylation of choline. Later Lipmann (2, 3) reported an enzyme system in extracts of pigeon liver which catalyzed the CoA and ATP-dependent acetylation of sulfanilamide by acetate. The iden...

HE conversion of 2-amino-4-hydroxypteridine into isoxanthopterin in wildtype Drosophila melanogaster has been demonstrated and investigated by several groups (FORREST, GLASSMAN and MITCHELL 1956; HADORN and SCHWINCK 1956; NAWA, TAIRA and SAKAGUCHI 1958). This reaction is catalyzed by an enzyme which will also catalyze the oxidation of hypoxanthine through xanthine into uric acid, xanthopterin i...

A novel approach to developing enantioselective enzymes for use in organic chemistry has been devised which is independent of structural or mechanistic aspects. The underlying idea is to combine appropriate methods of random mutagenesis, gene expression, and high-throughput screening for enantioselectivity. If these actions are performed in repetitive cycles, an evolutionary pressure is created...

Studies on the functionality of muscle proteins in gelation mechanisms of structured meat products during the last three decades are briefly reviewed. Among muscle proteins, myosin is primarily the most important protein for gelation, whereas actin plays a complementary role in gelation when it coexists with myosin. The combined data of gelation and denaturation indicate that the gelation of my...

Gentamicin C complex is a mixture of aminoglycoside antibiotics used worldwide to treat severe Gram-negative bacterial infections. Despite its clinical importance, the enzymology of its biosynthetic pathway has remained obscure. We report here insights into the four enzyme-catalyzed steps that lead from the first-formed pseudotrisaccharide gentamicin A2 to gentamicin X2, the last common interme...

Activation reactions of this type are catalyzed by enzymes from various sources (2-6) and specific activating enzymes may be required for each amino acid (2). The first highly purified, activating enzyme was a tryptophan-activating enzyme from beef pancreas, studied by Davie et al. (7). The isolation and properties of a tyrosine-activating enzyme from hog pancreas (8) are described in this report.