A Possible O2 Reduction Mechanism

major features of the X-ray structure at the dioxygen reduction site, contribute to the stability of the oxygenated form of this enzyme, and this stability has been confirmed by the resonance Raman investigations described above (Kitagawa and Ogura, 1997). The major features are trigonal planar coordination of Cub, and the close proximity of both Tyr244 and heme a to heme as. 

Tyr244 is connected to the matrix space by a hydrogen bond network which is likely to be a facile proton transfer path, and this is described below. Thus Tyr244 could be an effective proton donor to the O2 bound to 

PROTON TRANSER IN BOVINE HEART CYTOCHROME C OXIDASE 

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