We have performed Fe K-edge X-ray absorption spectroscopy measurements at BM08 in carboxy myoglobin (MbCO) and in a membrane pigment-protein complex (the bacterial photosynthetic reaction center, RC) embedded in trehalose glasses and in a weakly interacting matrix (solution and PVA, respectively). We have concluded that the incorporation into a trehalose glass strongly hinders the dynamics of both MbCO and RC. Alterations in the EXAFS functions, probably due to subtle structural modifications, are observable in the trehalose matrix. The data collected in the RC seem to indicate that, at variance with the PVA matrix, the trehalose matrix can protects against X-ray damage even under high irradiation.
G. Venturoli, F. Francia, L. Giachini, F. Boscherini, L. Cordone, G. Palazzo (2006). Matrix effect on the local structure of Fe in myoglobin, cytochrome c and photosynthetic reaction center. SC-1976..
Matrix effect on the local structure of Fe in myoglobin, cytochrome c and photosynthetic reaction center. SC-1976.
VENTUROLI, GIOVANNI;FRANCIA, FRANCESCO;GIACHINI, LISA;BOSCHERINI, FEDERICO;
2006
Abstract
We have performed Fe K-edge X-ray absorption spectroscopy measurements at BM08 in carboxy myoglobin (MbCO) and in a membrane pigment-protein complex (the bacterial photosynthetic reaction center, RC) embedded in trehalose glasses and in a weakly interacting matrix (solution and PVA, respectively). We have concluded that the incorporation into a trehalose glass strongly hinders the dynamics of both MbCO and RC. Alterations in the EXAFS functions, probably due to subtle structural modifications, are observable in the trehalose matrix. The data collected in the RC seem to indicate that, at variance with the PVA matrix, the trehalose matrix can protects against X-ray damage even under high irradiation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
