Show simple item record

dc.contributor.advisorErman, Jamesen_US
dc.contributor.authorNuevo, Marites Roqueen_US
dc.date.accessioned2016-02-05T14:48:33Z
dc.date.available2016-02-05T14:48:33Z
dc.date.issued1993
dc.identifier.urihttp://commons.lib.niu.edu/handle/10843/15265
dc.descriptionIncludes bibliographical references (pages [96]-97)en_US
dc.description.abstractThe kinetics of the reduction of excess CcP Compound I concentration by a limiting amount of horseheart ferro- cytochrome c at 25°C has been studied using stopped-flow techniques. The reaction was monitored at 437 nm using 200 mM ionic strength potassium phosphate buffer, pH 7.5. A fast phase related to the electron transfer from ferro- cytochrome c to the radical site of CcP Compound I to form an inter- mediate, CcP Compound IIF, was observed. The pseudo-first order rate constant for this reduction step increased with CcP Compound I concentration in a hyperbolic manner and was independent of the initial ferrocytochrome c concentration. The observed intracomplex electron transfer rate associated with this phase was 602 + 4 s'1. Comparison of the spectrum of the intermediate in the Soret region with that of CcP Compound I confirms that the reduction of the radical rather than the oxyferryl heme occurs in the first reduction step at this ionic strength. The rate of reduction of CcP Compound I by excess ferrocytochrome c was also measured under the same conditions. The reaction was biphasic with the radical being reduced in the fast phase and the oxyferryl heme reduced in the slow phase. The intracomplex electron transfer rate for the first reduction step was 652 + 1 s'1. The structure of the intermediate formed in the fast phase was also determined based on the spectrum in the Soret region. Intermediate ionic strength buffers (10, 40, 60, and 100 mM) were also used to determine the rate of reduction at conditions where the amount of CcP Compound I is in excess over the ferrocytochrome c concentration. Reduction of the oxyferryl heme of CcP Compound I was observed in the fast phase using these buffers. The change in the initial site of reduction in CcP Compound I by ferrocytochrome c from the Fe(IV) to the radical site probably occurs between 100 mM and 200 mM ionic strength.en_US
dc.format.extentx, 109 pagesen_US
dc.language.isoengen_US
dc.publisherNorthern Illinois Universityen_US
dc.rightsNIU 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.en_US
dc.subject.lcshCytochrome oxidaseen_US
dc.subject.lcshReduction (Chemistry)en_US
dc.subject.lcshCytochrome cen_US
dc.titleA stopped-flow investigation of the reduction of excess cytochrome c peroxidase compound I by limiting amounts of horseheart cytochrome c at high ionic strengthen_US
dc.type.genreDissertation/Thesisen_US
dc.typeTexten_US
dc.contributor.departmentDepartment of Chemistryen_US
dc.description.degreeM.S. (Master of Science)en_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record