A spectroscopic and thermal stability study on the interaction between putrescine and bovine trypsin.
A spectroscopic and thermal stability study on the interaction between putrescine and bovine trypsin.
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DOI：
10.1016/j.ijbiomac.2016.10.009
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发表时间：
2017
影响因子：
8.2
通讯作者：
L. Momeni;B. Shareghi;A. Saboury;S. Farhadian;F. Reisi
中科院分区：
文献类型：
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作者：
L. Momeni;B. Shareghi;A. Saboury;S. Farhadian;F. Reisi
用稳态热稳定性、本征荧光、紫外可见光谱、远、近紫外圆二色谱和动力学技术以及分子对接技术研究了腐胺与牛胰酶的相互作用。计算了胰酶-腐胺络合物的Stern-Volmer猝灭常数，表明腐胺通过静态荧光猝灭与胰酶相互作用。结合分子对接技术得到的热变和熵变值表明，氢键和范德华力在结合过程中起主要作用。腐胺偶联后，酶的Vmax和kcat/Km值增大。紫外吸收光谱、圆二色谱和荧光技术的结果表明，腐胺的结合引起了胰酶微环境的变化，导致了其二级结构的变化。与天然胰酶相比，胰酶-腐胺复合体的热稳定性有更大的提高。胰酶-腐胺复合体热稳定性的提高可能是由于腐胺修饰后表面疏水性降低和氢键形成增加所致，表现为紫外吸收增加和荧光光谱猝灭。结论：腐胺的结合改变了胰酶的结构和功能。
The interaction of putrescine with bovine trypsin was investigated using steady state thermal stability, intrinsic fluorescence, UV–vis spectroscopy, far and near- UV circular dichroism and kinetic techniques, as well as molecular docking. The Stern-Volmer quenching constants for the trypsin- putrescine complex were calculated revealing that putrescine interacted with trypsinviathe static fluorescence quenching. The enthalpy and entropy change values and the molecular docking technique revealed that hydrogen bonds and van der Waals forces play a major role in the binding process. Upon putrescine conjugation, theVmaxvalue and thekcat/Kmvalues of the enzyme was increased. The results of UV absorbance, circular dichroism and fluorescence techniques demonstrated that the micro environmental changes in trypsin were induced by the binding of putrescine, leading to changes in its secondary structure. The thermal stability of trypsin- putrescine complex was enhanced more significantly, as compared to that of the native trypsin. The increased thermal stability of trypsin- putrescine complex might be due to the lower surface hydrophobicity and the higher hydrogen bond formation after putrescine modification, as reflected in the increase of UV absorbance and the quenching of fluorescence spectra. It was concluded that the binding of putrescine changed trypsin structure and function.