Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.4 (deaminase)
 5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The influence of ampicillin and chloramphenicol administered intraperitoneally singly or in combination on the protein content and the activities of hepatic esterase and amidase have been investigated in rats. The results have been compared to the effects of phenobarbitone (inducer) and p-nitrophenyl-phosphate (inhibitor) of hepatic hydrolases. Ampicillin pretreatment reduced protein level and amidase activity by 3.5% each but caused a significant increase (8.1%) in total esterase activity compared to controls. Chloramphenicol treatment caused an overall decrease in protein level, esterase and amidase activities respectively by 11%, 11%, and 35% over controls. Combined administration of both drugs resulted in a decrease in protein, esterase and amidase activities by 11.5%, 12.5%, and 41.2% respectively, thus mimicking the effects obtained with chloramphenicol alone. The changes induced by administration of the drugs particularly in combination on the constituent enzymes of rat hepatic hydrolases may affect the ability of the body to deal with exposure to environmental chemicals if extrapolated to man.
 ...
PMID:Chloramphenicol and ampicillin-induced changes in rat hepatic esterase and amidase activities. 1088 7

Chloramphenicol and florfenicol are broad-spectrum antibiotics. Although the bacterial resistance mechanisms to these antibiotics have been well documented, hydrolysis of these antibiotics has not been reported in detail. This study reports the hydrolysis of these two antibiotics by a specific hydrolase that is encoded by a gene identified from a soil metagenome. Hydrolysis of chloramphenicol has been recognized in cell extracts of Escherichia coli expressing a chloramphenicol acetate esterase gene, estDL136. A hydrolysate of chloramphenicol was identified as p-nitrophenylserinol by liquid chromatography-mass spectroscopy and proton nuclear magnetic resonance spectroscopy. The hydrolysis of these antibiotics suggested a promiscuous amidase activity of EstDL136. When estDL136 was expressed in E. coli, EstDL136 conferred resistance to both chloramphenicol and florfenicol on E. coli, due to their inactivation. In addition, E. coli carrying estDL136 deactivated florfenicol faster than it deactivated chloramphenicol, suggesting that EstDL136 hydrolyzes florfenicol more efficiently than it hydrolyzes chloramphenicol. The nucleotide sequences flanking estDL136 encode proteins such as amidohydrolase, dehydrogenase/reductase, major facilitator transporter, esterase, and oxidase. The most closely related genes are found in the bacterial family Sphingomonadaceae, which contains many bioremediation-related strains. Whether the gene cluster with estDL136 in E. coli is involved in further chloramphenicol degradation was not clear in this study. While acetyltransferases for chloramphenicol resistance and drug exporters for chloramphenicol or florfenicol resistance are often detected in numerous microbes, this is the first report of enzymatic hydrolysis of florfenicol resulting in inactivation of the antibiotic.
 ...
PMID:Inactivation of chloramphenicol and florfenicol by a novel chloramphenicol hydrolase. 2275 66