The effect of the solvent viscosity on the migration of small molecules through the structure of myoglobin

Article type: Research Article

Authors: Feitelson, Jehuda^a | Yedgar, S.^b

Affiliations: [a] Department of Physical Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel | [b] Department of Biochemistry, Hadassah Medical School, Jerusalem 91010, Israel

Note: [] Accepted by: Editor A. Maroudas

Abstract: The migration rate of small molecules through the structure of proteins can be monitored by quenching the light emitted from an excited optical probe located within the protein. In the present study we examined the influence of the solvent viscosity on the migration rate of the quencher anthraquinone sulfonate through myoglobin towards an excited Zn protoporphyrin molecule at the binding site of the protein. The solvent viscosity was increased by adding dextrans of different molecular weight but forming isoviscous solutions. The results demonstrate that the migration rate in the protein decreases with increasing solvent viscosity. This suggests that the fluctuations on the protein structure, which make the above migration possible, are affected by the solvent macroviscosity.

Keywords: Solvent Viscosity, Myoglobin Dynamics

DOI: 10.3233/BIR-1991-281-210

Journal: Biorheology, vol. 28, no. 1-2, pp. 99-105, 1991