Molecular aspects of the interaction of spermidine and alpha-chymotrypsin

作者：Farhadian Sadegh; Shareghi Behzad^*; Saboury Ali A; Babaheydari Ali Kazemi; Raisi Fatame; Heidari Ehsan

来源：International Journal of Biological Macromolecules, 2016, 92: 523-532.

DOI：10.1016/j.ijbiomac.2016.07.069

• alpha-Chymotrypsin
• Spectroscopic techniques
• Dynamic quenching
• Docking simulations
• Thermal stability

Polyamines such as spermidine are essential for survival. The purpose of the present study was to investigate how spermidine could influence the conformation, thermal stability and the activity of alpha-chymotrypsin. The influence of spermidine on the structure and stability of alpha-Chymotrypsin (alpha-Chy) explored using different spectroscopy method and molecular docking simulations. The stability and activity of alpha-Chy were increased in the presence of spermidine. Increasing of the alpha-Chy absorption in the presence of spermidine was as a result of the formation of a spermidine - alpha-Chy complex. The results of fluorescence spectroscopic measurements suggested that spermidine has a vigorous ability to quench the intrinsic fluorescence of alpha-Chy through the dynamic quenching procedure. Near and Far-UV CD studies also confirmed the transfer of aromatic residues to a more flexible environment. The absorption increasing of alpha-Chy in the presence of spermidine was as a result of the formation of spermidine alpha-Chy complex. Molecular docking results also revealed the presence of one binding site with a negative value for the Gibbs free energy of the binding of spermidine to alpha-Chy. Further, the docking study revealed that van der Waals interactions and hydrogen bonds play a main role in stabilizing the complex.

• 出版日期2016-11