The heme domain of cellobiose oxidoreductase: a one-electron reducing system
2003 (English)In: Biochimica et Biophysica Acta - Bioenergetics, ISSN 0005-2728, E-ISSN 1879-2650, Vol. 1604, no 1, 47-54 p.Article in journal (Refereed) Published
Phanerochaete chrysosporium cellobiose oxidoreductase (CBOR) comprises two redox domains, one containing flavin adenine dinucleotide (FAD) and the other protoheme. It reduces both two-electron acceptors, including molecular oxygen, and one-electron acceptors, including transition metal complexes and cytochrome c. If the latter reacts with the flavin, the reduced heme b acts merely as a redox buffer, but if with the b heme, enzyme action involves a true electron transfer chain. Intact CBOR fully reduced with cellobiose, CBOR partially reduced by ascorbate, and isolated ascorbate-reduced heme domain, all transfer electrons at similar rates to cytochrome c. Reduction of cationic one-electron acceptors via the heme group supports an electron transfer chain model. Analogous reactions with natural one-electron acceptors can promote Fenton chemistry, which may explain evolutionary retention of the heme domain and the enzyme's unique character among secreted sugar dehydrogenases.
Place, publisher, year, edition, pages
2003. Vol. 1604, no 1, 47-54 p.
cellobiose, cellobiose dehydrogenase, heme domain, ascorbate, cellobiose oxidoreductase, cytochrome c, heme b, electron transfer, lignin, phanerochaete chrysosporium, phanerochaete-chrysosporium, quinone oxidoreductase, glucose-oxidase, dehydrogenase, oxygen, activation, reduction, kinetics
IdentifiersURN: urn:nbn:se:kth:diva-22424DOI: 10.1016/s0005-2728(03)00023-9ISI: 000182280600006OAI: oai:DiVA.org:kth-22424DiVA: diva2:341122
QC 201005252010-08-102010-08-10Bibliographically approved