Preparation of unsymmetrically labeled oxygen molecules and their use of elucidate oxygen metabolism

摘要

A novel technique has been developed to synthesize in large quantities an O(sub 2) molecule that is unsymmetrically labeled with the oxygen isotopes oxygen-16 and oxygen-18. This unusual molecule, (sup 16)O(sup 18)O, has been utilized as a unique spectroscopic probe of the mechanism of metabolism in living organisms. Preparation of this molecule requires prior synthesis of the exotic precursor hypofluorous acid, HOF, and an improved method for synthesizing this precursor has recently been developed that permits the preparation of essentially unlimited quantities of the labeled oxygen. This, in turn, has made it practical to use this oxygen in Raman-spectroscopic studies of the mechanism by which O(sub 2) is reduced by the enzyme cytochrome oxidase, a key step in the metabolic utilization of oxygen by living organisms. The results indicate that the interaction of O(sub 2) with the iron of the enzyme may be represented: Fe(sup 2+) + O(sub 2) (yields) Fe(sup 2+)-O(sub 2) (yields) Fe(sup 3+)-OOH(sup (minus)) (yields) Fe(sup 4+) = O (yields) Fe(sup 3+)-OH(sup (minus)).