CAJ | 학술논문

利用荧光光谱和FT-IR方法在体外研究了异嗪皮啶与人γ球蛋白(HGG)的相互作用,利用Sips和Gibbs-Helmholtz方程计算了不同温度下结合反应的亲和力常数和热动学参数,利用Docking方法研究了其相互作用模式.Sips图谱结果表明,异嗪皮啶与HGG之间主要存在两类结合位点,以及基于范德华力和氢键的非特异性的相互作用,而且结合反应是熵驱动的自发的放热结合过程.在297,303,310,317 K下的亲和力常数分别为10.708,9.152,7.084,5.386 L/mol.利用FT-IR光谱方法计算了在异嗪皮啶加入前后HGG二级结构的含量变化,结果表明加入异嗪皮啶后,蛋白质β结构含量降低,但是蛋白质典型的β-构型仍然保持.根据Forster能量转移理论,计算得到蛋白质色氨酸残基与异嗪皮啶的平均结合距离为3.57 nm.HGG可作为异嗪皮啶的体内转运蛋白.
이용형광광보화FT-IR방법재체외연구료이진피정여인γ구단백(HGG)적상호작용,이용Sips화Gibbs-Helmholtz방정계산료불동온도하결합반응적친화력상수화열동학삼수,이용Docking방법연구료기상호작용모식.Sips도보결과표명,이진피정여HGG지간주요존재량류결합위점,이급기우범덕화력화경건적비특이성적상호작용,이차결합반응시적구동적자발적방열결합과정.재297,303,310,317 K하적친화력상수분별위10.708,9.152,7.084,5.386 L/mol.이용FT-IR광보방법계산료재이진피정가입전후HGG이급결구적함량변화,결과표명가입이진피정후,단백질β결구함량강저,단시단백질전형적β-구형잉연보지.근거Forster능량전이이론,계산득도단백질색안산잔기여이진피정적평균결합거리위3.57 nm.HGG가작위이진피정적체내전운단백.
The interaction of isofraxidin with human immune gamma globulin (HGG) was studied in vitro by fluorescence spectra and FT-IR. The binding and thermodynamic parameters for the reaction were calculated according to Sips procedure and Gibbs-Helmholtz equation respectively at different tem-peratures. Molecular docking was used to calculate the interaction modes between isofraxidin and HGG. The Sips plots suggested that the binding of HGG to isofraxidin at 297, 303, 310 and 317 K was charac-terized by two binding sites with the average affinity constants k0 at 10.708, 9.152, 7.084, 5.386 L/mol, respectively. The binding process was exothermic, spontaneous and enthalpy driven. The binding was a non-specific interaction, mainly based on the interactions of Van der Waals forces and hydrogen bonds. The secondary structure compositions of free HGG and its isofraxidin complexes calculated quantita-tively by the FT-IR spectrum results indicated that the β-structure compositions of HGG decreased in the presence of isofraxidin, but the typical β structural conformation of HGG was still retentive. The average binding distance between isofraxidin and the tryptophan residues in HGG (3.57 nan) was obtained on the basis of the theory of Forster energy transfer. The experimental results indicat that HGG could be used as a transfer for isofraxidin in vivo.