Functionalized cellulose as a matrix for the synthesis of library of molecular receptors useful for screening of compounds with anti-histamine activity

The library of molecular receptors was formed by self-organization of N-heptanoylated dipeptides anchored in the regular fashion via aminophenylamino- 1,3,5-triazine linker to the surface of cellulose membrane. SPOT method was used for the synthesis of peptide library. As C-terminal amino acids of peptide fragments were attached: Ala, Pro and Phe, while as a N-terminal amino acids were applied all natural amino acids. DMT/NMM/TosO- was selected as a coupling reagent for synthesis of library of N-heptanoylated dipeptides. These constructs were used as a tool for distinguishing pharmaceutically active compounds acting on histamine receptors. In the studies as active compounds were tested: Doxylamine and Difenhydramine with histamine agonist activity, Ranitidine and Cimetidine with antagonist activity as well as Histamine – natural ligand. The binding of colourless ligands was monitored by staining with Brilliant Black used as reporter dye and quantitative colour measurement was performed in 256 grade gray scale by using Image-Quant software. Substantial differences in the ability of interactions of agonists and antagonists with bounding pockets were observed with selected molecular receptors. From 60 elements library of molecular receptors were selected 12, which were able to distinguish between agonists or antagonists. It has been found that even small changes (Leu residue vs Val residue) in the structure of molecular receptor influenced specificity of agonist or antagonist binding.