title: Protein-like proton exchange in a synthetic host cavity.
abstract: The mechanism of proton exchange in a metal-ligand enzyme active site mimic (compound 1) is described through amide hydrogen-deuterium exchange kinetics. The type and ratio of cationic guest to host in solution affect the rate of isotope exchange, suggesting that the rate of exchange is driven by a host whose cavity is occupied by water. Rate constants for acid-, base-, and water-mediated proton exchange vary by orders of magnitude depending on the guest, and differ by up to 200 million-fold relative to an alanine polypeptide. These results suggest that the unusual microenvironment of the cavity of 1 can dramatically alter the reactivity of associated water by magnitudes comparable to that of enzymes.
authors.affiliation: Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Department of Chemistry, University of California, Berkeley, CA 94720;
authors.forename: William M
authors.initials: WM
authors.lastname: Hart-Cooper
authors.affiliation: Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Department of Chemistry, University of California, Berkeley, CA 94720;
authors.forename: Carmelo
authors.initials: C
authors.lastname: Sgarlata
authors.affiliation: Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, CA 92093.
authors.forename: Charles L
authors.initials: CL
authors.lastname: Perrin
authors.affiliation: Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Department of Chemistry, University of California, Berkeley, CA 94720; fdtoste@berkeley.edu rbergman@berkeley.edu raymond@socrates.berkeley.edu.
authors.forename: F Dean
authors.initials: FD
authors.lastname: Toste
authors.affiliation: Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Department of Chemistry, University of California, Berkeley, CA 94720; fdtoste@berkeley.edu rbergman@berkeley.edu raymond@socrates.berkeley.edu.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Bergman
authors.affiliation: Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Department of Chemistry, University of California, Berkeley, CA 94720; fdtoste@berkeley.edu rbergman@berkeley.edu raymond@socrates.berkeley.edu.
authors.forename: Kenneth N
authors.initials: KN
authors.lastname: Raymond
mesh_terms: D000409:Alanine / Q000737:chemistry / Q000378:metabolism; D000577:Amides / Q000737:chemistry; D041961:Deuterium Exchange Measurement; D004798:Enzymes / Q000737:chemistry / Q000378:metabolism; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008958:Models, Molecular; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*; D011522:Protons; D012996:Solutions; D013997:Time Factors; D014867:Water
chemical_list: D000577:Amides; D004798:Enzymes; D011506:Proteins; D011522:Protons; D012996:Solutions; D014867:Water; D000409:Alanine
keywords: catalysis; hydrogen–deuterium exchange; noncovalent; proton; supramolecular