CORRELATION BETWEEN PROTEIN STABILITY AND CRYSTAL PROPERTIES OF DESIGNED ROP VARIANTS

Six variants of the ROP protein, designed with the aim to analyze by X -ray crystallography loop formation and core packing interactions in 4 -alpha-helical bundles, have been purified and a search of their cryst allization conditions has been carried out. Five mutants yield crystal s that are suitable for medium to high resolution X-ray diffraction st udies. For all mutants crystal size, sensitivity to X-irradiation and diffraction limit are correlated to their stability as determined by d ifferential scanning calorimetry, in a manner which is not yet underst ood in detail.