The sodium-dependent D-glucose transport protein of Helicobacter pylori.

摘要: Helicobacter pylori is a gram-negative pathogenic microaerophile with particular tropism for the mucosal surface of gastric epithelium. Despite its obligatory microaerophilic character, it can metabolize D-glucose and/or D-galactose in both oxidative and fermentative pathways via Na(+)-dependent secondary active transport, glucokinase enzymes pentose phosphate pathway. We have assigned transport glucose to protein product H. 1174 gene. The gene was heterologously expressed transport-deficient Escherichia coli strain, where activities radiolabelled D-glucose, 2-deoxy-D-glucose were restored, consistent expected specificity hexose uptake system pylori. D-mannose also identified as substrate. HP1174 purified reconstituted into proteoliposomes, sodium dependence sugar activity demonstrated. Additionally tryptophan/tyrosine fluorescence showed quenching by 2-deoxy-D-glucose, D-mannose, or presence ions. This first reported purification characterization an member TC 2.1.7 subgroup Major Facilitator Superfamily, constituting route entry nutrients A model derived three-dimensional structure paradigm family.