Gökoğlu Elmas, Budun Seniye Şura, Doyuran Bensu, Taskin-Tok Tugba
Faculty of Science, Department of Chemistry, Hacettepe University, Ankara, 06800, Turkey.
Faculty of Arts and Sciences, Department of Chemistry, Gaziantep University, Gaziantep, 27310, Turkey.
J Fluoresc. 2024 Jul 15. doi: 10.1007/s10895-024-03835-1.
The binding properties between vitamin B12 (vitB12, cyanocobalamin) and fibrinogen (Fib) were investigated by UV-vis absorption and steady-state/three-dimentional (3D) fluorescence spectra techniques as well as molecular docking. The experimental results showed that the intrinsic fluorescence of Fib quenched by vitB12 with static mechanism to form a non-fluorescent complex. The positive signs of thermodynamic parameters, ΔH (92.18 kJ/mol) and ΔS (433.5 J/molK), indicated that the hydrophobic forces were dominant in the binding mode. The molecular docking data were found to be in agreement with these experimental results and were confirmed by three hydrophobic interactions between the Trp430, Try390 residues of Fib and the vitamin. 3D spectra showed that fibrinogen undergoes a conformation change when it interacts with vitB12. Based on non-radiative energy transfer theory, binding distance was calculated to be 3.94 nm between donor (tryptophan residues of Fib) and acceptor (vitB12). The limit of detection (LOD) of vitB12 was calculated as 2.08 µM in the presence of fibrinogen. The relative standard deviation (RSD) of method was 4.28% for determinations (n = 7) of a vitB12 solution with the concentration of 7.80 µM.
采用紫外可见吸收光谱、稳态/三维（3D）荧光光谱技术以及分子对接技术，研究了维生素B12（vitB12，氰钴胺）与纤维蛋白原（Fib）之间的结合特性。实验结果表明，vitB12使Fib的内源荧光发生静态猝灭，形成非荧光复合物。热力学参数ΔH（92.18 kJ/mol）和ΔS（433.5 J/molK）的正值表明，疏水作用力在结合模式中起主导作用。分子对接数据与这些实验结果一致，并通过Fib的Trp430、Try390残基与维生素之间的三种疏水相互作用得到证实。三维光谱表明，纤维蛋白原与vitB12相互作用时会发生构象变化。基于非辐射能量转移理论，计算得出供体（Fib的色氨酸残基）与受体（vitB12）之间的结合距离为3.94 nm。在存在纤维蛋白原的情况下，vitB12的检测限（LOD）计算为2.08 µM。对于浓度为7.80 µM的vitB12溶液进行7次测定，该方法的相对标准偏差（RSD）为4.28%。
