Protein dynamics. An overview on flash-photolysis over broad temperature ranges.
Ligand binding kinetics to heme-proteins between 40 and 300 K point to a regulatory role of protein dynamics. A protein-specific susceptibility of the heme-iron reactivity to dynamic fluctuations emerges from the distribution of reaction enthalpies derived from flash-photolysis measurements below ca. 180 K; we quantify it in terms of 'intramolecular viscosity', postulating that narrow low-temperature enthalpy distributions correspond to low internal viscosity and vice versa. The thermal evolution of ligand binding kinetics suggests, with other results, an interplay between high-frequency transitions of the amino acid side chains and low-frequency collective motions as a possible regulatory mechanism of protein dynamics.
Di Iorio
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EE
Laboratorium für Biochemie I, Eidgenössische Technische Hochschule, Zurich, Switzerland.
D002248:Carbon Monoxide / Q000378:metabolism; D008956:Models, Chemical; D010782:Photolysis; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature; D013816:Thermodynamics
D011506:Proteins; D002248:Carbon Monoxide