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15N solid-state NMR as a probe of flavin H-bonding.

ABSTRACT: Flavins mediate a wide variety of chemical reactions in biology. To learn how one cofactor can be made to execute different reactions in different enzymes, we are developing solid-state NMR (SSNMR) to probe the flavin electronic structure, via the (15)N chemical shift tensor principal values (?(ii)). We find that SSNMR has superior responsiveness to H-bonds, compared to solution NMR. H-bonding to a model of the flavodoxin active site produced an increase of 10 ppm in the ?(11) of N5, although none of the H-bonds directly engage N5, and solution NMR detected only a 4 ppm increase in the isotropic chemical shift (?(iso)). Moreover SSNMR responded differently to different H-bonding environments, as H-bonding with water caused ?(11) to decrease by 6 ppm, whereas ?(iso) increased by less than 1 ppm. Our density functional theoretical (DFT) calculations reproduce the observations, validating the use of computed electronic structures to understand how H-bonds modulate the flavin's reactivity.

SUBMITTER: Cui D

PROVIDER: S-EPMC3156030 | biostudies-literature | 2011 Jun

REPOSITORIES: biostudies-literature

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15N solid-state NMR as a probe of flavin H-bonding.

Cui Dongtao D Koder Ronald L RL Dutton P Leslie PL Miller Anne-Frances AF

The journal of physical chemistry. B 20110527 24

Flavins mediate a wide variety of chemical reactions in biology. To learn how one cofactor can be made to execute different reactions in different enzymes, we are developing solid-state NMR (SSNMR) to probe the flavin electronic structure, via the (15)N chemical shift tensor principal values (δ(ii)). We find that SSNMR has superior responsiveness to H-bonds, compared to solution NMR. H-bonding to a model of the flavodoxin active site produced an increase of 10 ppm in the δ(11) of N5, although no ...[more]

PMID: 21619002

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