Title
The importance of the non-active site and non-periodical structure located histidine residue respect to the structure and function of exo-inulinase
Author
Maryam Rezaei Arjomand, Gholamreza Ahmadian, Mehran Habibi-Rezaei, Malihe Hassanzadeh, Ali Asghar Karkhane, Ali Akbar Moosavi-Movahedi, Massoud Amanlou
Year
2017
Journal
International Journal of Biological Macromolecules
Abstract
Here, we have studied the role of a histidine residue with the lowest solvent accessibility among other histidine residues at the end of a short connecting structure (189AELH192) of the catalytic domain of the exo-inulinase through creation of H192A mutant. Site-directed mutagenesis method was applied to create the mutant enzyme. Molecular dynamics (MD) simulations, spectroscopic, calorimetric and kinetics analysis were used to study the structural and functional consequences of His192 substitution. Accordingly, the thermo-stabilities and catalytic performance were decreased upon H192A mutation. In silico and experimental approaches evidently confirm that His192 residue of exo-inulinase possesses structural and functional importance regardless of the lack of direct interaction with the substrate or involvement in the catalytic activity of exo-inulinase.
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Biochemistry