Glucose transport in Streptococcus agalactiae and its inhibition by lactoperoxidase-thiocyanate-hydrogen peroxide.
Transport of 2-deoxyglucose or glucose in Streptococcus agalactiae was strongly inhibited if the cells were first exposed to a combination of lactoperoxidase-thiocyanate-hydrogen peroxide (LP-complex). The inhibition was completely reversible with dithiothreitol. N-ethylmaleimide and p-chloromercuribenzoate inhibited sugar transport, and the inhibition was also reversible with dithiothreitol. Sodium fluoride also inhibited sugar transport. Glucolysis was completely inhibited, and dithiothreitol completely reversed the inhibition. Phosphoenolpyruvate-dependent phosphotransferase activity in S. agalactiae was not strongly inhibited by the LP-complex. Interference of the entry of glucose into cells of S. agalactiae by the LP-complex could well account for its growth inhibitory properties with this organism. The inhibition of glucose transport by the LP-complex and its reversibility with dithiothreitol suggest the modification of functional sulfhydryl groups in the cell membrane as a cause of transport inhibition.
D001693:Biological Transport, Active / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002729:Chloromercuribenzoates / Q000494:pharmacology; D003847:Deoxyglucose / Q000378:metabolism; D004229:Dithiothreitol / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D005459:Fluorides / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism*; D006019:Glycolysis / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007784:Lactoperoxidase / Q000494:pharmacology*; D010101:Oxygen Consumption; D010544:Peroxidases / Q000494:pharmacology*; D010728:Phosphoenolpyruvate / Q000378:metabolism; D010770:Phosphotransferases / Q000378:metabolism; D013292:Streptococcus agalactiae / Q000201:enzymology / Q000378:metabolism*; D013861:Thiocyanates / Q000494:pharmacology*
D002729:Chloromercuribenzoates; D013861:Thiocyanates; D010728:Phosphoenolpyruvate; D003847:Deoxyglucose; D006861:Hydrogen Peroxide; D007784:Lactoperoxidase; D010544:Peroxidases; D010770:Phosphotransferases; D005947:Glucose; D005033:Ethylmaleimide; D005459:Fluorides; D004229:Dithiothreitol