School of Science, Xi'an Jiaotong University, Xi'an 710049, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2013 Oct;114:231-5. doi: 10.1016/j.saa.2013.05.061. Epub 2013 May 29.
In this paper, a new mathematical equation of lg(F0-F)/F=1/nlg[P]+1/nlgKa, which was used to obtain interaction parameters (the binding constant Ka and the number of binding sites n) between the protein and the small molecule ligand by using the ligand as a fluorescence (FL) probe, was constructed for the first time. The interaction parameters between myoglobin, catalase, lysozyme, bovine serum albumin (BSA) and luminol were obtained by this equation with luminol used as a FL probe, showing that the binding constants Ka were 8.78×10(5), 4.47×10(5), 4.21×10(4) and 3.95×10(4) respectively, and the number of binding sites n approximately equaled to 1.0 for myoglobin, catalase, and 2.0 for lysozyme, BSA. The interactions of ferritin, ovalbumin, aldolase, chymotrypsinogen and ribonuclease with luminol were also studied by this method. The binding constants Ka were at 10(4)-10(5) level, and the number of binding sites n mostly approximately equaled to 2.0. The binding ability of luminol to the studied proteins followed the pattern: myoglobin>aldolase>ferritin>ovalbumin>catalase>ribonuclease>lysozyme>BSA>chymotrypsinoge.
本文首次构建了一个新的数学方程 lg(F0-F)/F=1/nlg[P]+1/nlgKa，该方程用于通过将配体用作荧光（FL）探针来获得蛋白质与小分子配体之间的相互作用参数（结合常数 Ka 和结合位点数 n）。使用荧光素作为 FL 探针，得到了肌红蛋白、过氧化氢酶、溶菌酶、牛血清白蛋白（BSA）和鲁米诺之间的相互作用参数，结果表明结合常数 Ka 分别为 8.78×10(5)、4.47×10(5)、4.21×10(4)和 3.95×10(4)，结合位点数 n 约等于 1.0 对于肌红蛋白、过氧化氢酶，而对于溶菌酶和 BSA 则约等于 2.0。还通过该方法研究了铁蛋白、卵清蛋白、醛缩酶、糜蛋白酶原和核糖核酸酶与鲁米诺的相互作用。结合常数 Ka 在 10(4)-10(5)水平，结合位点数 n 大多约等于 2.0。鲁米诺与研究蛋白的结合能力遵循以下模式：肌红蛋白>醛缩酶>铁蛋白>卵清蛋白>过氧化氢酶>核糖核酸酶>溶菌酶>BSA>糜蛋白酶原。
