6533b831fe1ef96bd1299095

RESEARCH PRODUCT

Myoglobin embedded in saccharide amorphous matrices: water-dependent domains evidenced by small angle X-ray scattering

Alessandro LongoLorenzo CordoneSergio GiuffridaGrazia Cottone

subject

Photosynthetic reaction centreSucroseGLASS-TRANSITIONGeneral Physics and AstronomyInfrared spectroscopyRhodobacter sphaeroideschemistry.chemical_compoundRhodobacter sphaeroidesScattering Small AngleSpectroscopy Fourier Transform InfraredPHOSPHOLIPID-BILAYERREACTION CENTERSPhysical and Theoretical ChemistrySettore CHIM/02 - Chimica FisicabiologyScatteringSmall-angle X-ray scatteringMyoglobinTrehaloseWaterbiology.organism_classificationPROTEIN DYNAMICSTrehaloseMOLECULAR-DYNAMICS SIMULATIONAmorphous solidCrystallographyMyoglobinchemistryTHERMAL-DENATURATIONNEUTRON-SCATTERINGCARBOXY-MYOGLOBINEXTERNAL MATRIXTREHALOSE-COATED MBCO

description

We report Small Angle X-ray Scattering (SAXS) measurements performed on samples of carboxy-myoglobin (MbCO) embedded in low-water trehalose glasses. Results showed that, in such samples, "low-protein" trehalose-water domains are present, surrounded by a protein-trehalose-water background; such finding is supported by Infrared Spectroscopy (FTIR) measurements. These domains, which do not appear in the absence of the protein and in analogous sucrose systems, preferentially incorporate the incoming water at the onset of rehydration, and disappear following large hydration. This observation suggests that, in organisms under anhydrobiosis, analogous domains could play a buffering role against the daily variations of the atmospheric moisture. The reported results are rationalized by assuming sizably different protein-matrix coupling in trehalose with respect to sucrose, analogous to the one suggested for the photosynthetic reaction centre from Rhodobacter sphaeroides (F. Francia et al., J. Am. Chem. Soc., 2008, 130, 10240-10246).

yearjournalcountryeditionlanguage
2010-05-14
10.1039/b926977khttp://hdl.handle.net/10447/53932