An examination of the inhibitory effects of N-iodoacetylglucosamine on Escherichia coli and isolation of resistant mutants.
1. After incubation of Escherichia coli with N-iodo[1,2-(14)C(2)]acetylglucosamine, 95-99% of the (14)C taken up by whole cells is located in a cold-trichloroacetic acid-soluble fraction. Two major components of this fraction are S-carboxymethylcysteine and S-carboxymethylglutathione. The same compounds accumulate during incubation with iodo[(14)C]acetate but not with iodo[(14)C]acetamide. The amount of (14)C associated with a cold-trichloroacetic acid-insoluble fraction are comparable for all three alkylating agents. After incubation with iodo[(14)C]acetamide, 50% of the label bound to whole cells is recoverable in a cold-trichloroacetic acid-insoluble fraction. 2. Uptake and incorporation of (14)C from [U-(14)C]glycerol is blocked at an early stage by N-iodoacetylglucosamine. No specific inhibition of macromolecular synthesis could be demonstrated. 3. Mutants selected for resistance to iodoacetate are partially resistant to iodoacetate and N-iodoacetylglucosamine, but show no resistance to iodoacetamide. 4. Mutants selected for resistance to N-iodoacetylglucosamine are not resistant to iodoacetate or iodoacetamide, and are defective in their ability to grow on N-acetylglucosamine. Resistance to N-iodoacetylglucosamine is not absolute, and depends on the presence of glucose or certain other sugars; there is no resistance during growth on maltose, glycerol or succinate. 5. Absolute resistance can be achieved by selecting for a second mutation conferring resistance during growth on maltose; double mutants isolated by this procedure are unable to grow on N-acetylglucosamine and grow poorly on glucosamine. Resistant single mutants have a slightly diminished uptake of N-acetyl[1-(14)C]glucosamine, but in resistant double mutants the uptake of both [1-(14)C]glucosamine and N-acetyl[1-(14)C]glucosamine is severely diminished. 6. These observations are consistent with the presence of two permeases for N-acetylglucosamine, one that also permits uptake of glucosamine and another that allows entry of methyl 2-acetamido-2-deoxy-alpha-d-glucoside. N-Iodoacetylglucosamine can gain entry to the cell by both permeases.
D002247:Carbon Isotopes; D002850:Chromatography, Gel; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology; D005944:Glucosamine / Q000378:metabolism / Q000494:pharmacology*; D005990:Glycerol / Q000378:metabolism; D006601:Hexoses / Q000378:metabolism; D007461:Iodoacetates / Q000378:metabolism / Q000494:pharmacology*; D026901:Membrane Transport Proteins / Q000378:metabolism; D009154:Mutation; D014238:Trichloroacetic Acid
D002247:Carbon Isotopes; D006601:Hexoses; D007461:Iodoacetates; D026901:Membrane Transport Proteins; D014238:Trichloroacetic Acid; D005944:Glucosamine; D005990:Glycerol