New calcium-sensitive ligand for nuclear magnetic resonance spectroscopy

Targeting the colchicine site in tubulin through cyclohexanedione derivatives

Cyclohexanedione derivatives, a new family of colchicine-site binders, have been further explored with the aid of docking studies, resulting in compounds with improved solubility and K_a value for tubulin.

NMR study of pradimicin derivative BMY-28864 and its interaction with calcium ions in D2O

The dynamic structure of the antifungal antibiotic pradimicin BMY-28864 in D2O and its interaction with calcium ions were analyzed using one- and two-dimensional 1H nuclear magnetic resonance (NMR). Spectra indicate extensive self-association of molecules in the solution. Two-component spectra were observed simultaneously in a very dilute solution, suggesting equilibrium of two aggregative states. The addition of CaCl2 caused a number of changes in NMR spectra. Therefore we concluded that pradimicin BMY-28864 could form a complex with the Ca2+ ion, causing a movement of the equilibrium. The position of the bound calcium ion is determined indirectly by observing how the NMR shift affects protons that are close to the binding site. The stoichiometry of Ca2+ ion to the Pradimicin molecule for the Ca(2+)-saturated complex is verified to be 1:2. Signal broadening and changes in chemical shift in the 1H NMR spectroscopy of BMY-28864 are assumed to be related to changes in the molecular aggregate conformation.

Construction of a 28-mm 1H/13C probe and actively shielded Z-gradient set for operation in a 9.4 T/89 mm magnet

In this work, we present a new RF and gradient assembly for operation in a 9.4 Tesla/89 mm magnet. This assembly was designed in order to enable 1H-NMR perfusion studies that are based on proton-observed carbon-edited approaches or gradient selected double quantum coherence. The RF portion of this probe assembly is comprised of a modified Alderman-Grant coil and a saddle coil operating at 400 and 100 MHz, respectively. These coils are surrounded by an actively shielded Z gradient, which also allows for the use of gradient-based water suppression without the need for carbon selection. We demonstrate that this probe can be used to implement gradient selected double quantum coherence experiments resulting in a high degree of water suppression.