Electrochemical studies of a few active center model system of ferredoxins in presence of surfactants and liposomes

Abstract

Ferredoxins are a class of Fe-S proteins involved in electron transfer in a number of vital biological processes. The redox potential value of the active centre of ferredoxin is crucial in controlling its electron transfer behaviour. The hydrophobicity and charge nature of the microenvironment arround the active centre is considered to influence its redox potential significantly. The objective of this thesis is to investigate how hydrophobic and charge nature the active centre of ferredoxin influences its redox potential and proton coupled electron transfer behaviour. Determination of diffusion coefficient on to the electrode surface of the active centre analogoues in different mediums is another aspect of study. We have synthesized (using reported procedure) active centre analogoues of ferredoxin viz. [Fe4S4(SPh)4]2-, [Fe4S4(SCH2CH2COO)4]6- [Fe4S4(SCH2CH2OH)4]2- and [Fe4Se4(SPh)4]2-. Surfactants Cetyltrimethylammonium bromide (CTAB), Triton X-100 (TX-100) and Sodium dodecyl sulphate (SDS) were used to provide various charge and hydrophobicity around the active centre. Details electrochemical investigations have also been done in liposomes and microemulsions. The chapter wise brackup of the investigation has been illustrated bellow: Chapter I is an introduction to the thesis and gives a brief description of ferredoxins and its model systems. The chapter includes brief introduction of model cell membranes like micelles, liposomes and microemulsions. The chapter also describes various experimental techniques used in our study. Chapter II includes Cyclic voltammetric and Osteryoung square wave voltammetric studies of [Fe4S4(SPh)4]2- in dimethylformamide in presence of different surfactant molecules and inside CTAB film on glassy carbon electrode surface along with the determination of diffusion coefficient of the cluster on to the electrode surface. Chapter III contains Cyclic voltammetric and Osteryoung square wave voltammetric studies of [Fe4S4(SCH2CH2COO)4]6- in various aqueous micellar solutions in mercaptide...