氧氟沙星和左氟沙星与人血清白蛋白的相互作用研究

用光谱技术研究了水溶液中氧氟沙星(OFLX)和左氟沙星(LVFX)与人血清白蛋白相互作用的机制.荧光猝灭法测得的结果表明反应的结合常数为KOFLX＝0.482×105L@mol-1,KLVFX=0.529×105L@mol-1,结合位点数nOFLX＝0.72,nLVFX=0.74.按照Fōorster非辐射能量转移理论得到药物-蛋白之间的结合距离分别为rOFLX=2.94nm,nVFX=2.85 nm.实验结果说明OFLX与LVFX在体内与蛋白结合直到运输到受体部位这一环节基本相同.     

Modification of short-range repulsive interactions in ReaxFF reactive force field for Fe-Ni-Al alloy

The short-range repulsive interactions of any force field must be modified to be applicable for high energy atomic collisions because of extremely far from equilibrium state when used in molecular dynamics (MD) simulations. In this work, the short-range repulsive interaction of a reactive force field (ReaxFF), describing Fe-Ni-Al alloy system, is well modified by adding a tabulated function form based on Ziegler-Biersack-Littmark (ZBL) potential. The modified interaction covers three ranges, including short range, smooth range, and primordial range. The short range is totally predominated by ZBL potential. The primordial range means the interactions in this range is the as-is ReaxFF with no changes. The smooth range links the short-range ZBL and primordial-range ReaxFF potentials with a taper function. Both energies and forces are guaranteed to be continuous, and qualified to the consistent requirement in LAMMPS. This modified force field is applicable for simulations of energetic particle bombardments and reproducing point defects' booming and recombination effectively.     

甲磺酸培氟沙星与人血清白蛋白相互作用研究

以光谱技术和微量热技术相结合的方法研究水溶液中甲磺酸培氟沙星分子及其铜离子存在时与人血清白蛋白之间结合作用的机制,用荧光淬灭法测得两反应的结合常数分别为K＝1.7 × l0⁵L.mol^-1和1.61×10⁵L.mol^-1，结合位点数1.05和1.5。甲磺酸培氟沙星对人血清白蛋白的猝灭为静态猝灭。依据Fōrster非辐射能量转移机制，得到甲磺酸培氟沙星—人血清白蛋白间的结合距离。用同步荧光技术考察甲磺酸培氟沙星对人血清白蛋白构象的影响。微量热法测得甲磺酸培氟沙星与人血清白蛋白反应的△H≈0, △S﹥0 表明其作用力主要为疏水力,而甲磺酸培氟沙星分子在铜离子存在时与人血清白蛋白反应的△H﹤0并且△S﹥0表明主要是静电作用。由于焓熵互补的作用,两反应的自由能没有发生大的变化。