Lee, Alfred Daniel Jesse; (1990) A comparative study of the structures of electron-transfer proteins using NMR. Doctoral thesis (Ph.D), UCL (University College London).

Text A_comparative_study_of_the_str.pdf Download (7MB)

Abstract

This thesis is a study of the structure of horse-heart cytochrome-c, and the relationship of its structure to function, using primarily nmr spectroscopy. It is demonstrated that nmr spectroscopy is a useful tool for the study of proteins in solution, and an assignment procedure for nmr spectra of proteins is described. By the use of this procedure, the ¹H nmr spectrum of native ferricytochrome-c is assigned. The assignment of the ¹H nmr spectrum of tfa- modified cytochrome-c is given, and compared to that of the native protein. Using the assignments prepared for native ferri- and ferrocytochrome-c, and for the modified protein in both oxidation states, an attempt is made to describe and explain the structure and dynamics of cytochrome-c. Comparisons are made of NH/ND exchange rates, the aromatic ring flip of Tyr97, Gd³⁺ ion binding sites and denaturation temperatures between the native and tfa-modified cytochrome-cs. The effect of amino acid substitutions between horse and tuna cytochrome-cs upon chemical shift of NH and CαH protons is also studied. The results from these experiments provide a basis for the discussion of the relative importance of electrostatic interactions in determining the structure and dynamics of cytochrome-c. It is concluded that the structure of cytochrome-c is extremely rigid, and that its structure is determined more by close range forces than long-range electrostatic forces. It is believed that the techniques described in this thesis will be of general applicability to the study of electron-transfer proteins.

Download activity - last month

Export as CSVJSONXML

Download activity - last 12 months

Export as CSVXMLJSON

Downloads by country - last 12 months

Export as CSVJSONXML

Archive Staff Only

View Item