DESIGNING PEPTIDE BY MOLECULAR RECOGNITION THEORY AS AFFINITY ADSORPTION LIGAND FOR PEPTIDE PURIFICATION IN AFFINITY CHROMATOGRAPHY

摘要

An ''antisense'' peptide corresponding to the ''sense'' peptide, angiotensin II, was designed by the Molecular Recognition Theory (MRT) and synthesized by the solid phase peptide synthesis method. The complementarity of peptides specified by ''sense'' and ''antisense'' strands of DNA of MRT were adapted in a computer program and the Kyte and Doolittle's hydropathy scoring system was used as the hydrophobicity indicator of amino acids in this study. The prototypical system used for evaluating the interaction between such peptide pairs involved testing for the binding of angiotensin II (AII) and its antisense peptide, AII-AS (Ile-Ala-Asn-Val-Asn-Met-Gly-Glu). AII-AS peptide was attached to EAH-Sepharose 4B support, and the binding constants between AII-AS with AII and with AII antagonist ([Ser1, Ile8]-AII) were respectively determined. The higher binding affinity between AII antagonist with AII-AS was also supported by a preliminary molecular modeling calculation. A mathematical modeling for affinity chromatography was adapted to compare the experimental results and to demonstrate the effects of the pore diffusion as the rate determining step on the performance of the anti-sense affinity column. The results of this study could provide a novel approach to affinity ligand design for bioseparation by MRT and molecular modeling. [References: 29]