Phosphorylation and metabolism of sucrose and its five linkage-isomeric alpha-D-glucosyl-D-fructoses by Klebsiella pneumoniae
2001
Thompson, J. | Robrish, S.A. | Pikis, A. | Brust, A. | Lichtenthaler, F.W.
Not only sucrose but the five isomeric alpha-D-glucosyl-D-fructoses trehalulose, turanose, maltulose leucrose, and palatinose are utilized by Klebsiella pneumoniae as energy sources for growth, thereby undergoing phosphorylation by a phosphoenolpyruvate-dependent phosphotransferase system uniformly at O-6 of the glucosyl moiety. Similarly maltose, isomaltose, and maltitol, when exposed to these conditions, are phosphorylated regiospecifically at O-6 of their non-reducing glucose portion. The structures of these novel compounds have been established unequivocally by enzymatic analysis, acid hydrolysis, FAB negative ion spectrometry, 1H and 13C NMR spectroscopy. In cells of K. pneumoniae, hydrolysis of sucrose 6-phosphate is catalyzed by sucrose 6-phosphate hydrolase from Family 32 of the glycosylhydrolase superfamily. The five 6'-O-phosphorylated alpha-D-glucosyl-fructoses are hydrolyzed by an inducible (approximately 49-50 Kda) phospho-alpha-glucosidase from Family 4 of the glycosylhydrolase superfamily.
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