Functional equivalence of monomeric (shark) and dimeric (bovine) cytochrome c oxidase.

Journal Article (Journal Article)

Cytochrome c oxidase isolated from hammerhead shark red muscle is monomeric in relation to the dimeric form of isolated bovine cytochrome c oxidase but in other ways bears a close resemblance to the enzyme isolated from mammalian tissue [1, 2]. Comparative studies of shark and bovine cytochrome c oxidase were extended to address the degree of functional similarity between the monomeric (shark) and dimeric (bovine) enzymes in the kinetics of peroxide binding and in the extent to which the catalytic action of the enzymes in vesicles can establish a proton gradient. Although the kinetics of peroxide binding and the proton pumping processes are complex, the dimeric and monomeric forms are quite similar with respect to these functional attributes. The kinetic heterogeneity of the process of peroxide binding is expressed in the shark enzyme as well as in the bovine enzyme, and both types of enzymes in vesicles can generate transmembrane proton gradients. On this basis we conclude that the dimeric state of isolated cytochrome c oxidase from mammalian sources is not essential for its function in vitro.

Full Text

Duke Authors

Cited Authors

  • Bickar, D; Lehninger, A; Brunori, M; Bonaventura, J; Bonaventura, C

Published Date

  • March 1, 1985

Published In

Volume / Issue

  • 23 / 3-4

Start / End Page

  • 365 - 372

PubMed ID

  • 2410569

Electronic International Standard Serial Number (EISSN)

  • 1873-3344

International Standard Serial Number (ISSN)

  • 0162-0134

Digital Object Identifier (DOI)

  • 10.1016/0162-0134(85)85047-9


  • eng