title: Allosteric initiation and regulation of catalysis with a molecular knot.
abstract: Molecular knots occur in DNA, proteins, and other macromolecules. However, the benefits that can potentially arise from tying molecules in knots are, for the most part, unclear. Here, we report on a synthetic molecular pentafoil knot that allosterically initiates or regulates catalyzed chemical reactions by controlling the in situ generation of a carbocation formed through the knot-promoted cleavage of a carbon-halogen bond. The knot architecture is crucial to this function because it restricts the conformations that the molecular chain can adopt and prevents the formation of catalytically inactive species upon metal ion binding. Unknotted analogs are not catalytically active. Our results suggest that knotting molecules may be a useful strategy for reducing the degrees of freedom of flexible chains, enabling them to adopt what are otherwise thermodynamically inaccessible functional conformations.
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: Vanesa
authors.initials: V
authors.lastname: Marcos
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Stephens
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: Javier
authors.initials: J
authors.lastname: Jaramillo-Garcia
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: Alina L
authors.initials: AL
authors.lastname: Nussbaumer
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: Steffen L
authors.initials: SL
authors.lastname: Woltering
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: Alberto
authors.initials: A
authors.lastname: Valero
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Lemonnier
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: Iñigo J
authors.initials: IJ
authors.lastname: Vitorica-Yrezabal
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK. david.leigh@manchester.ac.uk.
authors.forename: David A
authors.initials: DA
authors.lastname: Leigh