Ribonuclease Activity of an Artificial Catalyst That Combines a Ligated Cu(II) Ion and a Guanidinium Group at the Upper Rim of a cone-Calix[4]arene Platform

J Org Chem. 2015 Jun 5;80(11):5887-93. doi: 10.1021/acs.joc.5b00965. Epub 2015 May 22.

Abstract

A cone-calix[4]arene derivative, featuring a guanidinium group and a Cu(II) ion ligated to a 1,4,7-triazacyclononane (TACN) ligand at the 1,3-distal positions of the upper rim, effectively catalyzes the cleavage of 2-hydroxypropyl p-nitrophenyl phosphate (HPNP) and a number of diribonucleoside 3',5'-monophosphates (NpN'). Kinetic and potentiometric measurements support the operation of a general-base/general-acid mechanism and demonstrate that the hydroxo form of the ligated Cu(II) ion is the sole catalytically active species. Rate enhancements relative to the background hydrolysis reaction at 1 mM catalyst concentration are 6 × 10(5)-fold for HPNP and cluster around 10(7)-fold with the most favorable catalyst-NpN' combinations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biochemical Phenomena
  • Calixarenes / chemistry*
  • Catalysis
  • Copper / chemistry*
  • Guanidine / chemistry*
  • Heterocyclic Compounds / chemistry*
  • Organometallic Compounds / chemistry*
  • Organophosphates
  • Phenols / chemistry*
  • Ribonucleases / chemistry*
  • Ribonucleosides / chemistry*

Substances

  • 2-(hydroxypropyl)-4-nitrophenyl phosphate
  • Heterocyclic Compounds
  • Organometallic Compounds
  • Organophosphates
  • Phenols
  • Ribonucleosides
  • calix(4)arene
  • Calixarenes
  • 1,4,7-triazacyclononane
  • Copper
  • Ribonucleases
  • Guanidine