Enzyme-like kinetics of ferryloxy myoglobin formation in films on electrodes in microemulsions. J. Phys. Chem. B 2005, 109, 24457
Date
2005Author
Guto Peterson M.
Rusling James F.
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
Covalently linked films of the ferric heme protein myoglobin and poly-l-lysine on pyrolytic graphite electrodes reacted with tert-butylhydroperoxide (tBuOOH) to form ferryloxy protein species according to Michaelis−Menten enzyme kinetics. Rotating disk voltammetry data obtained in microemulsions, micellar solution, and buffers revealed a strong influence of water phase acidity on kinetic parameters. Microemulsion and surfactant type had a much smaller influence on reaction kinetics, possibly because the reaction takes place entirely in a water environment surrounding Mb in the films in all fluids. A large apparent Michaelis kcat in microemulsions with neutral water phases was offset by much weaker binding as shown by larger protein−substrate dissociation constants (Km). Acidic SDS microemulsions and pH 2 buffer provided the most efficient reaction conditions as judged by the ratio kcat/Km. Apparent kinetic constants are most likely governed by acidity-controlled protein conformations and their binding with tBuOOH in the intermediate protein−substrate complex.
URI
http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/27831http://www.ncbi.nlm.nih.gov/pubmed/16375448
http://pubs.acs.org/doi/abs/10.1021/jp054621w
Citation
Peterson M. Guto and James F. Rusling. Enzyme-like kinetics of ferryloxy myoglobin formation in films on electrodes in microemulsions. J. Phys. Chem. B 2005, 109, 24457, GUTO, DR. PETERSON MOMANYI , J. Phys. Chem. B 2005, 109, 24457 , (2005) copy at http://profiles.uonbi.ac.ke/petersonguto/publications/peterson-m-guto-and-james-f-rusling-enzyme-kinetics-ferryloxy-myoglobin-foJ Phys Chem B. 2005 Dec 29;109(51):24457-64.
Publisher
Department of Chemistry