Hyde J E, Walker I O
Nucleic Acids Res. 1974 Feb;1(2):203-15. doi: 10.1093/nar/1.2.203.
The reactivities of the two cysteine thiol groups of calf thymus F3 histone were investigated using 5,5'-dithiobis-[2- nitrobenzoic acid], (DTNB). In isolated histone, both thiol groups were available for reaction. However, analysis of reaction profiles of native deoxyribonucleohistone, (DNH), in various solvent conditions, together with gel electrophoresis studies of DNH modified with DTNB, showed that only one of the thiol groups is normally modified by the reagent. If NaCl is present (above 1.OM) the other thiol group can also be modified. The reactivities of both groups were largely independent of the degree of DNH supercoiling and of the binding of F3 to the DNA.
利用5,5'-二硫代双-[2-硝基苯甲酸]（DTNB）研究了小牛胸腺F3组蛋白两个半胱氨酸巯基的反应活性。在分离的组蛋白中，两个巯基均可参与反应。然而，对天然脱氧核糖核组蛋白（DNH）在不同溶剂条件下的反应曲线分析，以及对用DTNB修饰的DNH进行的凝胶电泳研究表明，通常该试剂仅能修饰其中一个巯基。如果存在NaCl（浓度高于1.0M），另一个巯基也能被修饰。两个巯基的反应活性在很大程度上与DNH的超螺旋程度以及F3与DNA的结合无关。
