| Autor: |
Shanmugam M; Chemistry Department, Northwestern University, Evanston, Illinois 60208-3113, USA., Zhang B, McNaughton RL, Kinney RA, Hille R, Hoffman BM |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of the American Chemical Society [J Am Chem Soc] 2010 Oct 13; Vol. 132 (40), pp. 14015-7. |
| DOI: |
10.1021/ja106432h |
| Abstrakt: |
The formaldehyde-inhibited Mo(V) state of xanthine oxidase (I) has been studied for four decades, yet it has not proven possible to distinguish unequivocally among the several structures proposed for this form. The uniquely large isotropic hyperfine coupling for (13)C from CH(2)O led to the intriguing suggestion of a direct Mo-C bond for the active site of I. This suggestion was supported by the recent crystal structures of glycol- and glycerol-inhibited forms of aldehyde oxidoreductase, a member of the xanthine oxidase family. (1)H and (2)H ENDOR spectra of I(C(1,2)H(2)O) in H(2)O/D(2)O buffer now have unambiguously revealed that the active-site structure of I contains a CH(2)O adduct of Mo(V) in the form of a four-membered ring with S and O linking the C to Mo and have ruled out a direct Mo-C bond. Density functional theory computations are consistent with this conclusion. We interpret the large (13)C coupling as resulting from a "transannular hyperfine interaction". |
| Databáze: |
MEDLINE |
| Externí odkaz: |
|
