Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The metabolic pathways of p-nitroanisole, 4-nitro-m-cresol and methyl parathion in Malaysian prawns (Macrobrachium rosenbergii), ridgeback prawns (Sicyonia ingentis) and crayfish (Procambarus clarkii) were compared. 2. The Malaysian prawns and ridgeback prawns were shown to O-demethylate 29% and 11%, respectively, of an accumulated level of p-nitroanisole, while crayfish were able to O-demethylate 98% of the accumulated level of nitroanisole. 4-Nitro-m-cresol oxidation was not detected in either prawn species. In contrast, 5-hydroxy-2-nitrobenzaldehyde was the major metabolite formed from nitrocresol metabolism by crayfish. 3. Both prawn species readily dearylated methyl parathion to form p-nitrophenol and p-nitrophenyl conjugates. Crayfish displayed a similar trend in methyl parathion metabolism. 4. Nitroreduction was observed in the metabolism of 4-nitro-m-cresol by ridgeback prawns, which excreted 4-nitroso-m-cresol as a minor product. Reduction products were not observed in the metabolism of the three substrates by Malaysian prawns or crayfish. 5. Conjugation was overall the dominant detoxication pathway observed in the decapods. Malaysian prawns conjugated p-nitrophenol and 4-nitro-m-cresol to form the corresponding beta-D-glucosides and sulphate monoesters. Ridgeback prawns formed beta-D-glucosides in small quantities, preferring conjugation of p-nitrophenol and 4-nitro-m-cresol to form sulphates and unknown conjugates through a unique conjugation pathway. Crayfish conjugated the phenolic substrates to form exclusively the beta-glucosides. 6. The unknown conjugates formed by ridgeback prawns had chromatographic properties similar to the corresponding beta-D-glucosides but were refractory to the deconjugation by alpha- or beta-glucosidase, beta-galactosidase, aryl sulphatase and beta-glucuronidase. Phenolic conjugation ability appeared to follow the order of ridgeback prawns greater than Malaysian prawns greater than crayfish.
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PMID:Comparative metabolism of nitroaromatic compounds in freshwater, brackish water and marine decapod crustaceans. 343 90

A new variant type of regulatory activator and relevant promoters (designated capR, Pr and Po) involved in the metabolism of phenolic compounds were cloned from Pseudomonas putida KCTC1452 by using PCR. The deduced amino acid sequence of CapR revealed a difference in nine amino acids from the effector binding domain of DmpR. To measure effector specificity, plasmids were constructed in such a way that the expression of luc gene for firefly luciferase or lacZ for beta-galactosidase as a reporter was under the control of capR. When Escherichia coli transformed with the plasmids was exposed to phenol, dramatic increases in the activity of luciferase or beta-galactosidase were observed in a range of 0.01-1 mM. Among various phenolic compounds tested, other effective compounds included catechol, 2-methylphenol, 3-methylphenol, 4-methylphenol, 2-chlorophenol, 4-chlorophenol, 2-nitrophenol, resorcinol, and 2, 5-dimethylphenol. The results indicate that CapR has effector specificity different from other related activators, CatR and DmpR. Waste water and soil potentially containing phenolic compounds were also tested by this system and the results were compared with chemical and GC data. The present results indicate that the biosensor consisting of capR and the promoters may be utilized for the development of a phenolic compounds-specific biosensor in monitoring the environmental pollutant.
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PMID:A new variant activator involved in the degradation of phenolic compounds from a strain of Pseudomonas putida. 1289 Jun 9

We herein report the development of a recombinant bacterial biosensor for the rapid and easy detection of phenolic compounds in the field. A plasmid was designed to encode a beta-galactosidase reporter gene under the control of capR, an activator involved in phenolic compound degradation. The construct was transformed into Escherichia coli, and transformed cells were stored after being freeze-dried in the presence of sucrose. For detection of phenolic compounds, the cells were rehydrated, and used instantly, without any growth step. In the presence of 0.1 microM-10mM phenol, we observed a red color from hydrolysis of chlorophenol red beta-D-galactopyranoside (CPRG) or an indigo color from hydrolysis of X-galactopyranoside (X-gal). Other phenolic compounds could be detected by this system, including catechol, 2-methylphenol, 2-chlorophenol, 3-methylphenol, 2-nitrophenol, and 4-chlorophenol. These results suggest that this novel bacteria biosensor may be useful for easy, on-site detection of phenolic compounds without the need for unwieldy equipment or sample pretreatment. Indeed, biosensor systems involving beta-galactosidase-expressing freeze-dried recombinant bacteria could prove useful for the in situ detection of many more compounds in the future.
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PMID:Freeze-dried recombinant bacteria for on-site detection of phenolic compounds by color change. 1605 89