Y. Suzuki, S. Okamoto
Oct 25, 1967
Citations
2
Influential Citations
87
Citations
Quality indicators
Journal
The Journal of biological chemistry
Abstract
Abstract The chloramphenicol-inactivating enzyme in the multiple drug-resistant Escherichia coli carrying R factor produced two products from chloramphenicol in a cell-free system as well as in whole cells. Thin layer chromatography on silica gel, infrared spectroscopy, gas chromatography, and nuclear magnetic resonance analysis were carried out with the products. These products were identified as d-thero-2-dichloroacetamido-1-(p-nitrophenyl)-1-hydroxy-3-acetoxypropane and d-threo-2-dichloroacetamido-1-(p-nitrophenyl)-1,3-diacetoxypropane. It was shown that a chloramphenicol-resistant E. coli B selected in vitro and a sensitive strain of E. coli K-12 have no capacity to produce acetyl derivatives of chloramphenicol. Studies of the substrate specificity, heat stability, pH optimum, and chromatographic behavior of the chloramphenicol-acetylating enzyme from the multiple drug-resistant E. coli were carried out. The chloramphenicol-acetylating enzyme from the multiple drug-resistant E. coli produces a 3-O-acetyl derivative of chloramphenicol and converts the former to a 1,3-O, O-diacetyl derivative. The enzyme which produces the monoacetyl derivative was purified 120-fold, while the enzyme which produces the diacetyl derivative from the monoacetyl derivative was purified about 50-fold by the same purification procedures. It was not possible to decide whether one or two enzymes participate in the acetylation of chloramphenicol. When the multiple drug-resistant E. coli cells were converted to spheroplasts by lysozyme and ethylenediaminetetraacetate, the chloramphenicol-acetylating enzyme was not released into the medium under conditions in which the bulk of ribonuclease was released but β-galactosidase was not.