Candidate residue pairs

Natural variations in nuclear receptors reinforce the idea that nuclear receptors are good candidates for the creation of orthogonal ligand-receptor pairs. For example, the human retinoic acid receptor (RAR) has three subtypes RARa, RAR/ and RARy. These three subtypes differ at 87 amino acids but have only three divergent residues in the binding pocket [11] (Tab. 8.1). However, these three divergent residues are responsible for different binding profiles of synthetic retinoids... 

A pH-enzyme activity curve is shovm in Figure 9-1. Which of the following pairs of amino acids would be likely candidates as catalytic groups (See Primary Text, Table X-X for the pKa values of amino acid residues.)... 

It is well known that crown ethers form inclusion complexes with ion pairs in aprotic solvents. PhenyIboronic cyclic esters form adducts with amines 3, making them good candidates as convergent binding sites for amino groups. Linking these specific tnndinn sites with a chiral residue was the aim of this work as well as an examination... 

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