Interaction of phenols with old yellow enzyme. Physical evidence for charge-transfer complexes.
Year: 1976
Type: article
Abstract: Evidence is presented that the changes in absorption spectrum obtained on complex formation between Old Yellow Enzyme and phenolic compounds are due to charge-transfer interactions. The positive correlation between the energy of the long wavelength transition and the Hammett para constant with a series of para-substituted phenols indicates that the phenol is the charge-transfer donor and the oxidized flavin of the enzyme is the charge-transfer acceptor. The same conclusion is drawn from studies in which the flavin of the native enzyme, flavin mononucleotide, was replaced by a variety of artificial flavins of different oxidation-reduction potential. The effect of pH on the dissociation constant for the enzyme-ligand binding also indicates that it is the phenolate anion, rather than the conjugate acid, which is responsible for the charge-transfer interaction. The significance of these results is discussed relative to long wavelength absorbing species detected with other flavoproteins.
Source: Journal of Biological Chemistry
Authors: A S Abramovitz, V Massey
Institution: Johns Hopkins University
Language: English
Subfield: Physical and Theoretical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W1511190700