Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several species of fish from the genus Poeciliopsis differ dramatically in their response to the carcinogen N-nitrosodiethylamine (NDEA). The differential induction of tumors among genotypes exposed to NDEA may, in part, result from differences in liver cytochrome P450pj activity (the piscine equivalent of mammalian P450j). Evidence for the existence of cytochrome P450pj activity and mRNA expression has been found in several Poeciliopsis genotypes (species and strains). Biochemical evidence suggests that a microsomal cytochrome P450 enzyme catalyzes the metabolism of NDEA to acetaldehyde and other intermediates in Poeciliopsis. This reaction was inhibited by carbon monoxide, and required molecular oxygen and reducing equivalents (NADPH). Differences were found in maximal activity as well as temperature optima among genotypes. Poeciliopsis, a livebearing fish from desert streams of northwestern Mexico, appears to have thermal optima for cytochrome P450pj activity between 25 and 30 degrees C depending on the genotype. Western blot analysis (using anti-rat P450IIE1 antibodies) detected a 55-60 kd band in microsomes isolated from rat and Poeciliopsis. Using a 49mer probe specific for rat cytochrome P450j, Northern blots revealed a 3.3 kb mRNA from livers of a Poeciliopsis genotype and rat, but none in muscle mRNA from either organism. S1 nuclease protection assays, using the same probe, revealed that a mRNA fragment protected by the probe against digestion was induced on exposure of the whole organism to ethanol (via uptake from the aquatic environment). The assays also demonstrated that ethanol treatments both induced and suppressed this mRNA, depending on concentration and exposure time.
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PMID:Nitrosodiethylamine metabolism in the viviparous fish Poeciliopsis: evidence for the existence of liver P450pj activity and expression. 201 28

The substrate selectivities of three endonucleases were studied quantitatively using capillary zone electrophoresis to find one giving N2-ethyl(Et)-2'-deoxyguanosine-5'-monophosphate (5'-dGMP) and cyclic 1,N2-propano(CPr)-5'-dGMP from DNAs damaged by acetaldehyde (AA). Six 2'-deoxyribonucleoside-5'-monophosphates to be quantified in the hydrolysis solutions of DNAs, namely, Et-5'-dGMP, CPr-5'-dGMP, and four authentic ones, were completely separated using a 100 mM borate running buffer solution having an optimized pH of 9.67. Using the present method, nuclease reactions of nuclease S1 (NS1), nuclease P1 (NP1), and nuclease Bal 31 to 2'-deoxyribonucleoside-5'-monophosphates from damaged Calf thymus (CT-) DNAs were monitored. The CT-DNAs were prepared by treatment with AA to generate Et-guanine or CPr-guanine internally. Bal 31 hydrolyzed the damaged CT-DNAs to yield Et-5'-dGMP and CPr-5'-dGMP quantitatively. The two 5'-dGMP adducts were not detected in the hydrolysis solutions using NS1 or NP1. Bal 31 can be a suitable nuclease for analyzing DNA damages caused by AA.
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PMID:Evaluation of Type-A Endonucleases for the Quantitative Analysis of DNA Damage due to Exposure to Acetaldehyde Using Capillary Electrophoresis. 3010 84