Pollitt Sonia K, Schultz Peter G
Howard Hughes Medical Institute and, Department of Chemistry, University of California, Berkeley and, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (USA), Fax: (+1) 510-643-6890.
Angew Chem Int Ed Engl. 1998 Aug 17;37(15):2104-2107. doi: 10.1002/(SICI)1521-3773(19980817)37:15<2104::AID-ANIE2104>3.0.CO;2-Z.
Incorporation of an unnatural amino acid containing a photolabile group in the side chain allows specific interactions between two proteins to be prevented. The photocaged ras protein in which Asp 38 has been substituted by its β-nitrobenzyl ester (Nb) is unable to interact with its effector protein p120-GAP (see drawing below) although it has the same intrinsic GTPase activity. After photocleavage of the Nb group, 50% of the p120-GAP-dependent GTPase activity relative to the wild-type protein is restored.
在侧链中引入含有光不稳定基团的非天然氨基酸可阻止两种蛋白质之间的特异性相互作用。其中天冬氨酸38被其β-硝基苄酯（Nb）取代的光笼化ras蛋白，尽管具有相同的内在GTP酶活性，但无法与其效应蛋白p120-GAP相互作用（见下图）。Nb基团光裂解后，相对于野生型蛋白，50%的p120-GAP依赖性GTP酶活性得以恢复。
