Rush J, Konigsberg W H
Department of Molecular Biophysics and Biochemistry, Yale School of Medicine, New Haven, Connecticut 06510.
J Biol Chem. 1990 Mar 25;265(9):4821-7.
The photoaffinity compound 8-azido-dATP was used as a probe for the deoxyribonucleoside triphosphate-binding site of the large fragment of DNA polymerase I. Azido-dATP specifically modified a saturable binding site within the Klenow fragment, and each of the four natural deoxyribonucleoside triphosphate substrates competed with labeling at this site in proportion to its binding constant, as previously defined by equilibrium dialysis. Analysis of tryptic peptides after azido-dATP modification revealed five major cross-linking products, which apparently arose from five distinct photoadducts formed near Tyr-766.
光亲和化合物8-叠氮基-dATP被用作DNA聚合酶I大片段的脱氧核糖核苷三磷酸结合位点的探针。叠氮基-dATP特异性修饰了Klenow片段内的一个可饱和结合位点,并且四种天然脱氧核糖核苷三磷酸底物中的每一种都与该位点的标记竞争,其竞争比例与其结合常数成正比,如先前通过平衡透析所定义的那样。叠氮基-dATP修饰后胰蛋白酶肽段的分析揭示了五种主要的交联产物,它们显然来自于在Tyr-766附近形成的五种不同的光加合物。