Degradation enzymic, -elimination

The problem of a poor detection limit was caused by high background ATP and by the low sensitivity of the luciferin-luciferase (L-L) reagent. We have already developed an ATP elimination system using two ATP degrading enzymes (adenosine phosphate deaminase and apyrase) and a surfactant tolerant luciferase that was a mutated Luciola lateralis firefly luciferase. We optimized this elimination system, and investigated its suitability as a detection system. 

Recent reports have demonstrated that the white rot fungus Phanerochaete chrysosporlum produces a peroxldase-llke lignin degrading enzyme which can attack recalcitrant pesticides such as DDT and pesticide related compounds such as dioxin (2,3,7,8-tetrachlorodlbenzo-p-dloxln) (19). The fungi certainly eidilblt a broad range of degradatlve capabilities which deserve attention In future research efforts on biological elimination of pesticide wastes. 

Affinity data, like substrate or receptor binding constants, rate constants, like association/dissociation, and Michealis Menten constants, inhibition constants, especially Kj and IC50 values of different enzymes, pharmacokinetic parameters, like absorption rate constants, distribution parameters, clearance, rate constants of metabolic degradation, and elimination rate constants,... 

Galetin A, Burt H, Gibbons L and Houston JB (2006) Prediction of time-dependent CYP3 A4 drug-drug interactions impact of enzyme degradation, parallel elimination pathways, and intestinal inhibition. Drug Metab Dispos 34 166-175. 

There are only a few studies concerning the degradation and elimination of thiamin in animals. Most excess thiamin is eliminated as such by the kidneys. In a couple of older studies (Neal and Pearson 1964 Pearson et al. 1966), radioactive thiamin was administered in rats and the urines were analysed. Several radioactive degradation products of thiamin (2-methyl-4-amino-5-pyrimidine carboxylic acid and 4-methyl-thiazole-5-acetic acid), resulting from the cleavage between the thiazole and the pyrimidine moieties, were excreted in the urine. Other products were also detected but not identified. No enzymes specifically involved in thiamin degradation in mammals have been identified. 

Mercaptide Elimination. Kallio and Larson have described an oxidative degradation of methionine by a Pseudomonas. A pyridoxal phosphate enzyme eliminates methyl mercaptan and ammonia, leaving a-ketobutyrate. The methyl mercaptide is oxidized to dimethyl disulfide. 

Of interest were the observations that even though uricase was missing from human tissues, a portion of intravenously administered uric acid was never recovered (272-274). A recent report demonstrated that an appreciable quantity of uric acid was excreted into the human gastrointestinal tract, where it was broken down by the bacterial flora (275). This extra-renal excretion eliminated a considerable portion of the uric acid produced each day and may have accounted for the incomplete recovery of intravenously administered uric acid. However, it was demonstrated that uric acid was degraded enzymically by peroxidase-H 02 and other systems in tissues lacking uricase (276). Also, uric acid was oxidized in small quantities at physiological pH in the presence of a crude beef heart cytochrome oxidase... 

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