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001-es BibID:	BIBFORM005992
Első szerző:	Somogyi Béla (biofizikus)
Cím:	Forster-type energy transfer as a probe for changes in local fluctuations of the protein matrix / Bela Somogyi, Janos Matko, Sandor Papp, Jozsef Hevessy, G. Rickey Welch, Sandor Damjanovich
Dátum:	1984
Megjegyzések:	Much evidence, on both theoretical and experimental sides, indicates the importance of local fluctuations (in energy levels, conformational substates, etc.) of the macromolecular matrix in the biological activity of proteins. We describe here a novel application of the Forster-type energy-transfer process capable of monitoring changes both in local fluctuations and in conformational states of macromolecules. A new energy-transfer parameter, f, is defined as an average transfer efficiency, [E], normalized by the actual average quantum efficiency of the donor fluorescence, [phi D]. A simple oscillator model (for a one donor-one acceptor system) is presented to show the sensitivity of this parameter to changes in amplitudes of local fluctuations. The different modes of averaging (static, dynamic, and intermediate cases) occurring for a given value of the average transfer rate, [kt], and the experimental requirements as well as limitations of the method are also discussed. The experimental tests were performed on the ribonuclease T1-pyridoxamine 5'-phosphate conjugate (a one donor-one acceptor system) by studying the change of the f parameter with temperature, an environmental parameter expectedly perturbing local fluctuations of proteins. The parameter f increased with increasing temperature as expected on the basis of the oscillator model, suggesting that it really reflects changes of fluctuation amplitudes (significant changes in the orientation factor, k2, as well as in the spectral properties of the fluorophores can be excluded by anisotropy measurements and spectral investigations). Possibilities of the general applicability of the method are also discussed.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Energy Transfer Fluorescence Kinetics Mathematics metabolism Phosphorylase b Protein Conformation Proteins Ribonuclease T1 Spectrometry,Fluorescence Thermodynamics
Megjelenés:	Biochemistry. - 23 : 15 (1984), p. 3403-3411. -
További szerzők:	Matkó János (1952-) (biológus) Papp Sándor Hevessy József Welch, Rickey G. Damjanovich Sándor (1936-2017) (biofizikus)
Internet cím:	elektronikus változat
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