Coherent Experimental and Simulation Approach To Explore the Underlying Mechanism of Denaturation of Stem Bromelain in Osmolytes.

Autor: Rani A; Department of Chemistry, University of Delhi , Delhi 110 007, India., Taha M; Department of Chemistry, College of Science, Sultan Qaboos University , PO Box 36, PC 123 Muscat, Oman., Venkatesu P; Department of Chemistry, University of Delhi , Delhi 110 007, India., Lee MJ; Department of Chemical Engineering, National Taiwan University of Science & Technology , Taipei 10607, Taiwan.
Jazyk: angličtina
Zdroj: The journal of physical chemistry. B [J Phys Chem B] 2017 Jul 13; Vol. 121 (27), pp. 6456-6470. Date of Electronic Publication: 2017 Jun 30.
DOI: 10.1021/acs.jpcb.7b01776
Abstrakt: Characterization of a protein in the context of its environment is of crucial importance for a complete understanding of its function. Although biophysical techniques provide powerful tools for studying the stability and activity of the enzyme in the presence of various cosolvents, an approach of combining both experimental techniques and molecular dynamic (MD) simulations may lead to the mechanistic insight into the interactions governing the stability of an enzyme. The knowledge of these interactions can be further utilized for range of modifications in the wild form of an enzyme for various pharmaceutical applications. Herein, we employed florescence, UV-visible, circular dichroism (CD), dynamic light scattering (DLS) study, and MD simulations for comprehensive understanding of stem bromelain (BM) in the presence of betaine, sarcosine, arginine, and proline. The thermal stability of BM in the presence of 1 M of osmolytes is found to be in order: proline > betaine > buffer > arginine > sarcosine. BM gets more preferentially hydrated in the presence of betaine and proline than in sarcosine and arginine. Nonetheless, MD simulations suggest that betaine, sarcosine, and arginine at 1 M interact with the active site of BM through H-bonding except proline which are responsible for more disruption of active site. The distances between the catalytic site residues are 1.6, 1.9, 4.3, 5.0, and 6.2 Å for BM in proline, buffer, betaine, arginine, and sarcosine at 1 M, respectively. To the best of our knowledge, this is the first report on detailed unequivocal evidence of denaturation and deactivation of BM in the presence of methylamines and amino acids.
Databáze: MEDLINE