Download MendeleyInteractions of Isopenicillin N Synthase with Cyclopropyl-Containing Substrate Analogues Reveal New Mechanistic Insight.
Howard-Jones, A.R., Elkins, J.M., Clifton, I.J., Roach, P.L., Adlington, R.M., Baldwin, J.E., Rutledge, P.J.(2007) Biochemistry 46: 4755
- PubMed: 17397141
- DOI: https://doi.org/10.1021/bi062314q
- Primary Citation of Related Structures:
2IVI, 2IVJ - PubMed Abstract:
Isopenicillin N synthase (IPNS), a non-heme iron oxidase central to penicillin and cephalosporin biosynthesis, catalyzes an energetically demanding chemical transformation to produce isopenicillin N from the tripeptide delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-valine (ACV). We describe the synthesis of two cyclopropyl-containing tripeptide analogues, delta-(l-alpha-aminoadipoyl)-l-cysteinyl-beta-methyl-d-cyclopropylglycine and delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-cyclopropylglycine, designed as probes for the mechanism of IPNS. We have solved the X-ray crystal structures of these substrates in complex with IPNS and propose a revised mechanism for the IPNS-mediated turnover of these compounds. Relative to the previously determined IPNS-Fe(II)-ACV structure, key differences exist in substrate orientation and water occupancy, which allow for an explanation of the differences in reactivity of these substrates.
Organizational Affiliation:
Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK.
