chitohexaose and chitotriose

A specific substrate binding protein is located within the membrane of Streptomyces olivaceoviridis mycelia. After Triton extraction of the membrane, two forms of the protein (46.0 kD and 47.5 kD) were purified to apparent homogeneity by consecutive anionic exchange chromatographies. The results of competition interacted with N-acetylglucosamine and chitin oligomers (C2 to C6), but not with cellobiose nor glucose. Using surface plasmon resonance, the kinetic parameters of the 46 kD form of the binding protein were determined. This protein showed a very high affinity for N-acetylglucosamine (K(d) = 8.29 x 10(-9) mol/L) and for chitobiose (K(d) = 3.81 X 10(-6) mol/L), and the lowest one was for chitotriose (K(d) = 1.95 X 10(-5) mol/L). Comparisons of the dissociation and association rate constants indicated that the interaction of this protein with each ligand was controlled by the association rate. N terminal sequence indicated that this protein might belong to an ABC transporter system.

Topics: Acetylglucosamine; Amino Acid Sequence; Bacterial Proteins; Binding, Competitive; Chitin; Dimerization; Disaccharides; Kinetics; Molecular Sequence Data; Molecular Weight; Oligosaccharides; Protein Binding; Sequence Analysis, Protein; Streptomyces; Trisaccharides