Preparation of Catalytic Antibodies toward the Synthesis of Sequential Polypeptides

针对含有偶氮苯基和吡喃基的非天然氨基酸的多肽，分别制备了单抗。抗偶氮苯抗体仅与反式偶氮苯基结合，当反式偶氮苯光异构化为顺式时释放偶氮苯。结合位内发生了偶氮苯基团的光致异构化反应。利用这一独特的性质，人们尝试了氧化还原酶反应的光开关。当偶氮苯单元连接到NAD^+-衍生物时，后者在乙醇脱氢酶和黄递酶的氧化还原偶联酶反应中显示出正常的中介活性。当抗偶氮苯抗体加入到酶体系中时，在黑暗中中介活性被完全抑制，但在紫外光照射下，中介活性恢复。光循环可以重复多次。光控抗原-抗体反应是在云母平面上浇铸的含有偶氮苯基团的单层分子上进行的。用原子力显微镜(AFM)技术直接观察单层表面结合的抗体。抗体数量随着半抗原含量的增加而增加，说明结合是半抗原基的特异性结合。半抗原-抗体反应也在单层表面实现了光控制，抗核蛋白抗体结合了包括L-1-甲基丙氨酸在内的多种基团。但它不能结合D-1-吡喃丙氨酸。这一独特的性质将应用于非天然氨基酸的光学拆分。详细研究了与抗核仁抗体结合的核基的核基荧光。研究发现，激发态的吡喃基团仍留在结合部位内并发出荧光。

Monoclonal antibodies were raised against peptides containing nonnatural amino acids carring azobenzene group and pyrenyl group, respectively. The anti-azobenzene antibody bound only trans azobenzene group and released it when it was photoisomerized to the cis form. The photoisomerization of bound azobenzene group was found to take place inside the binding site. By using this unique property, a photoswitching of redox enzyme reaction was attempted. When an azobenzene unit was linked to an NAD^+-derivative, the latter showed normal mediation activity in a coupled redox enzyme reaction of alcohol dehydrogenase and diaphorase. When the anti-azobenzene antibody was added to the enzyme system, the mediation activity was completely suppressed in the dark, but the mediation activity recovered when the system was irradiated with UV light. The photocycle could be repeated many times.The photocontrolled antigen-antibody reaction was carried out on a monolayr containing azobenzene groups cast on a flat surface of mica. The antibodies bound on the monolayr surface were directly observed with atomic-force microscopy (AFM) technique. The number of antibody increased with increasing the hapten content, indicating that the binding is specific to the hapten groups. Photocontrol of the hapten-antibody reaction was also achieved on the monolayr surface.The anti-pyrenyl antibody bound a variety of pyrenyl derivatives including L-1-pyrenylalanine. But it did not bind D-1-pyrenylalanine. The unique property will be applied to optical resolution of nonnatural amino acids. The pyrenyl fluorescence of pyrenyl group bound to the anti-pyrenyl antibody was studied in detail. It was found that the pyrenyl group in the excited state remains inside the binding site and fluoresces.