24570-39-6Relevant articles and documents
Kinetics and thermodynamics of binding of a model tripeptide to teicoplanin and analogous semisynthetic antibiotics
Scrimin, Paolo,Tecilla, Paolo,Tonellato, Umberto,Verzini, Massimo,Andreini, Bianca Patrizia,Coutant, John E.,Zerilli, Luigi F.
, p. 6268 - 6272 (1996)
The thermodynamics and kinetics of binding of model tripeptides ε-N-acetyl-α-N-dansyl-L-Lys-D-Ala-D-Ala (ADLAA) or α-N,ε-N-diacetyl-L-Lys-D-Ala-D-Ala (AALAA) to teicoplanin (1a) and a series of semisynthetic derivatives with (1b-f) or devoid of (2a-g) the glycidic side arms and modified at the terminal amino acids of the peptide backbone have been studied by fluorescence or UV spectroscopy. The binding process is suggested to occur via a two-step mechanism. The first, fast process is likely governed by an electrostatic interaction between the C- and N-termini of the peptide chain of the substrate and of the antibiotic, respectively, while the second slower one, accounts for the formation of the hydrogen bonds responsible of the major contribution to the overall binding energy. The binding constants with all modified derivatives are smaller than that with native teicoplanin. Larger modification of the overall binding constant are observed when the sugar residues are removed and, to a lower extent, when the N-terminus of the peptide chain is acylated. The kinetic process is very little affected by the modifications introduced.
Thermodynamics and kinetics of dissociation of ligan-induced dimers of vancomycin antibiotics
McPhail, Deborah,Cooper, Alan
, p. 2283 - 2289 (1997)
The thermodynamics of dissociation of vancomycin and ristocetin dimers in the presence and absence of specific ligands has been studied by direct microcalorimetry over a range of temperature, pH and ionic strength conditions in H2O and D2O. Dimerization of these antibiotics is exothermic with large temperature dependence (ACP) and consequent entropy-enthalpy compensation effects that may be consistent with solvation changes associated with burial of non-polar surfaces during macromolecular association. For vancomycin, no significant ionic strength effects are observed, so non-specific electrostatic contributions are probably discounted, but pH and buffer effects on the thermodynamic parameters are consistent with hydrogen ion uptake and pK shift in the dimerization process. Vancomycin dimerization is significantly enhanced in the presence of specifically binding ligands: acetate, N-acetyl-D-Ala, and Nα,Ne-diacetyl-Lys-D-Ala-D-Ala, in increasing order of effectiveness. The dipeptide ligand N-acetyl-D-Ala-D-Ala promotes higher oligomerization and crystallization of the complex. Ristocetin, in contrast, displays no such ligand effects; it shows a slight reduction in dimerization in the presence of strongly binding Nα, Nε-diacetyl-Lys-D-Ala-D-Ala. This difference may reflect the need for flexibility in the antibiotic structure to allow ligand-induced aggregation. Eremomycin dimerizes strongly even in the absence of ligand. Dissociation of the vancomycin-Nα, Nε-diacetyl-Lys-D-Ala-D-Ala dimer complex is slow (kdiss ca. 0.005 s-1) and kinetics can be measured by conventional UV difference techniques.
Antibiotic activities and affinities for bacterial cell wall analogue of N-demethylvancomycin and its derivatives
Yan, Husheng,Qi, Dongfeng,Cheng, Xiaohui,Song, Zhengji,Li, Wenlan,He, Binglin
, p. 750 - 756 (2007/10/03)
N-Demethylvancomycin, which has been clinically used in China, is one member of vancomycin group (glycopeptide) antibiotics. It differs from vancomycin only in that methyl group on the amino group of the N-terminal residue of vancomycin has been replaced
