Studies on the Uptake of Hexose Phosphates

Abstract 2-Deoxy-d-glucose was taken up by Escherichia coli and was recovered from cell extracts largely as a material that behaved chromatographically as 2-deoxyglucose 6-phosphate. With 14C-labeled deoxyglucose, it was observed that radioactivity was taken up by the cell and partially released after 1 hour. No induction of transport for glucose 6-phosphate was observed on treatment of cells with 2-deoxyglucose, in spite of the apparent accumulation of intracellular 2-deoxyglucose 6-phosphate. By contrast, extracellular 2-deoxyglucose 6-phosphate, in low concentration, was an effective inducer of the hexose phosphate transport system. 2-Deoxyglucose inhibited growth of E. coli and also caused temporary growth stasis when glycerol or succinate was the carbon source. Cells growing in the presence of gluconate or pyruvate resisted these effects of 2-deoxyglucose. When glucose-grown cells were forced to adapt to glycerol or succinate as carbon source in the presence of 2-deoxyglucose, the lag period was prolonged for as long as several days. Often this was followed by rapid growth caused by spontaneous appearance of a mutant strain. The mutant was isolated and found to be resistant to growth inhibition by deoxyglucose.