Bernard Vitoux

17O NMR and FT‐IR study of the ionization state of peptides in aprotic solvents Application to Leu‐enkephalin

The ionization state of Leu‐enkephalin in DMSO and MeCN/DMSO (4/1) solution was studied by the combined use of 17O NMR and FT‐IR spectroscopy. After lyophilization or an aqueous solution at nearly neutral pH, Leu‐enkephalin essentially exists in the uncharged state in MeCN/DMSO (4/1) solution. In pure DMSO, only 40% of the Leu‐enkephalin molecules are in the zwitterionic state under the same conditions.

Crystallization and preliminary X-ray diffraction studies of d-glyceraldehyde-3-phosphate dehydrogenase from the hyperthermophilic archaeon Methanothermus fervidus

The homotetrameric holo-D-glyceraldehyde-3-phosphate dehydrogenase from the hyperthermophilic archaeon Methanothermus fervidus has been crystallized in the presence of NADP+ using the hanging-drop vapour-diffusion method. Crystals grew from a solution containing 2-methyl-2,4-pentanediol and magnesium acetate. A native data set has been collected to 2.1 A using synchrotron radiation and cryocooling. Diffraction data have been processed in the orthorhombic system (space group P21212) with unit-cell dimensions a = 136.7, b = 153.3, c = 74.9 A and one tetramer per asymmetric unit.