Molecular probes: what is the range of their interaction with the environment?
We performed pressure-tuning hole-burning experiments on a modified cytochrome c protein in a glycerol/buffer glass. The shift and the broadening of the holes were investigated for various frequencies within the inhomogeneous band. On the basis of a simple model, we were able to estimate the interaction range between chromophore and protein. It is approximately 4.5 A. The parameters that enter the model are the compressibility, the static mean-square displacement, the inhomogeneous width, and the average spectral shift per pressure. From this result and from our experiments on pressure-induced denaturing, we conclude that water molecules have to be brought very close to the chromophore during the denaturation process.
Lesch
H
H
Physik-Department E14, Lehrstuhl für Physik Weihenstephan, Technische Universität München, 85350 Freising, Germany.
Schlichter
J
J
Friedrich
J
J
Vanderkooi
J M
JM
D045304:Cytochromes c / Q000032:analysis* / Q000737:chemistry* / Q000528:radiation effects; D004777:Environment; D005456:Fluorescent Dyes / Q000032:analysis* / Q000737:chemistry* / Q000528:radiation effects; D006358:Hot Temperature; D007834:Lasers; D015335:Molecular Probes / Q000032:analysis* / Q000737:chemistry* / Q000528:radiation effects; D011312:Pressure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*; D015032:Zinc / Q000032:analysis / Q000737:chemistry / Q000528:radiation effects
D005456:Fluorescent Dyes; D015335:Molecular Probes; D045304:Cytochromes c; D015032:Zinc