MNM-1A-2 鏡面・非鏡面X線反射率測定によるタンパク吸着膜構造の統計学的評価(セッション 1A マイクロ・ナノスケールバイオ計測と医用応用)

Abstract

The purpose of this study is to investigate conformations of antibodies immobilized on three kinds of solid surfaces modified with APTES, AEAPTES or GA and their antigen-binding affinities. In the recent developments in biosensors, although the geometric structure of antibodies determines their sensitivity, few studies have focused on their conformations and its effect on their antigen-binding capacity due to a lack of applicable analysis techniques. In this work, specular and off-specular X-ray reflectivity measurement were employed, which enables us to analyze vertical and lateral multilayer structure. The results showed that the antigen-binding affinity on GA was highest among antibodies immobilized on three modified surfaces, although their conformations were almost the same as 'flat-on' analyzed by specular X-ray reflectivity. In contrast, lateral layer structure analysis by off-specular reflection revealed that protein layer on GA before antigen-binding had a relatively-long lateral correlation length and a low fractal dimension which would cause the reduction of steric hindrance for antigens' access to binding sites of antibodies.