Download MendeleyActive Site Mediated Elimination of Hydrogen Fluoride from a Fluorinated Substrate Analogue by Isopenicillin N Synthase
Grummitt, A.R., Rutledge, P.J., Clifton, I.J., Baldwin, J.E.(2004) Biochem J 382: 659
- PubMed: 15175003
- DOI: https://doi.org/10.1042/BJ20040529
- Primary Citation of Related Structures:
1UZW - PubMed Abstract:
Isopenicillin N synthase (IPNS) is a non-haem iron oxidase that catalyses the formation of bicyclic isopenicillin N from delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine (ACV). In this study we report a novel activity for the iron of the IPNS active site, which behaves as a Lewis acid to catalyse the elimination of HF from the fluorinated substrate analogue, delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-beta-fluorovaline (ACbetaFV). X-Ray crystallographic studies of IPNS crystals grown anaerobically with ACbetaFV reveal that the valinyl beta-fluorine is missing from the active site region, and suggest the presence of the unsaturated tripeptide delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-isodehydrovaline in place of substrate ACbetaFV. (19)F NMR studies confirm the release of fluoride from ACbetaFV in the presence of the active IPNS enzyme. These results suggest a new mode of reactivity for the IPNS iron centre, a mechanism of action that has not previously been reported for any of the iron oxidase enzymes.
Organizational Affiliation:
Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK.
