title: Purification and properties of the periplasmic glucose-binding protein of Pseudomonas aeruginosa.
abstract: A glucose-binding glycoprotein (GBP) from the periplasm of Pseudomonas aeruginosa was purified to homogeneity as judged by polyacrylamide gel electrophoresis, molecular sieve chromatography, and double-diffusion gel precipitation. It had an average molecular weight of 44,500 and an isoelectric point of 4.7. One mole of glucose was bound per mole of GBP with a dissociation constant of 0.35 muM. The binding of radioactive glucose by GBP was not significantly inhibited by 10-fold-higher concentrations of other carbohydrates; however, a number of related compounds were found to compete at 100-fold-higher concentrations. Amino acid analyses revealed predominant amounts of alanine, glutamate, and glycine and a low content of sulfur-containing amino acids. The carbohydrate moiety of GBP, comprising nearly 16% of the total weight, contained galactosamine, glucosamine, fucose, galactose, glucose, and mannose. A GBP-deficient mutant, strain MB723, was found to be defective in both membrane transport and glucose chemotaxis. Strain MB724, a revertant to GBP-positive phenotype, simultaneously recovered normal levels of both membrane functions.
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D002352:Carrier Proteins / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D002633:Chemotaxis; D005947:Glucose / Q000378:metabolism*; D007526:Isoelectric Point; D008970:Molecular Weight; D009154:Mutation; D011550:Pseudomonas aeruginosa / Q000032:analysis / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D005947:Glucose