Publication Date

1997

Document Type

Dissertation/Thesis

First Advisor

Erman, James E.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Chemistry

LCSH

Cytochrome oxidase; Peroxidase; Potassium fluoride; Chemical reactions

Abstract

The reactivity of potassium fluoride with wild-type cytochrome c peroxidase (CcP) and a mutant of cytochrome c peroxidase in which the distal histidine (His-52) is replaced with leucine [CcP(H52L)] has been studied from pH 4 to 8 in phosphate buffer at 0.1 M ionic strength. The spectrum of the fluoride complex of CcP(H52L) has been characterized. The kinetics of fluoride binding and the equilibrium constant for complex formation for both wild-type CcP and CcP(H52L) have been determined as a function of pH. The results of this study indicate that HF binds to wild-type CcP when the distal histidine is unprotonated. However, the association rate constant for fluoride binding to CcP(H52L) is only a factor of ten slower than binding to CcP at pH 5.5 and about the same at pH 8.0. A possible explanation is that another group, such as Arg-48 or the heme-bound hydroxide group in CcP(H52L), provides a function similar to that of His-52 in wild-type CcP. A major effect of the H52L mutation is to increase the rate of fluoride dissociation by a thousand-fold.

Comments

Includes bibliographical references (pages [53]-54)

Extent

x, 65 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

Download

Share

COinS