A Neoceptor Approach to Unraveling Microscopic Interactions Between the Human A2A Adenosine Receptor and Its Agonists

Chem Biol. 2005 Feb;12(2):237-47. doi: 10.1016/j.chembiol.2004.12.010.

Abstract

Strategically mutated neoceptors, e.g., with anionic residues in TMs 3 and 7 intended for pairing with positively charged amine-modified nucleosides, were derived from the antiinflammatory A(2A) adenosine receptor (AR). Adenosine derivatives functionalized at the 5', 2, and N(6) positions were synthesized. The T88D mutation selectively enhanced the binding of the chain-length-optimized 5'-(2-aminoethyl)uronamide but not 5'-(2-hydroxyethyl)uronamide, suggesting a critical role of the positively charged amine. Combination of this modification with the N(6)-(2-methylbenzyl) group enhanced affinity at the Q89D- and N181D- but not the T88D-A(2A)AR. Amino groups placed near the 2- or N(6)-position only slightly affected the binding to mutant receptors. The 5'-hydrazide MRS3412 was 670- and 161-fold enhanced, in binding and functionally, respectively, at the Q89D-A(2A)AR compared to the wild-type. Thus, we identified and modeled pairs of A(2A)AR-derived neoceptor-neoligand, which are pharmacologically orthogonal with respect to the native species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine / agonists*
  • Adenosine / chemical synthesis
  • Adenosine / chemistry
  • Adenosine / metabolism
  • Binding Sites
  • Humans
  • Ligands
  • Models, Molecular
  • Molecular Structure
  • Mutagenesis, Site-Directed
  • Protein Conformation
  • Receptor, Adenosine A2A / chemistry
  • Receptor, Adenosine A2A / genetics
  • Receptor, Adenosine A2A / metabolism*
  • Receptor, Adenosine A2A / ultrastructure
  • Recombinant Proteins / metabolism
  • Recombinant Proteins / ultrastructure

Substances

  • Ligands
  • Receptor, Adenosine A2A
  • Recombinant Proteins
  • Adenosine