title: Electrostatics-mediated α-chymotrypsin inhibition by functionalized single-walled carbon nanotubes.
abstract: The α-chymotrypsin (α-ChT) enzyme is extensively used for studying nanomaterial-induced enzymatic activity inhibition. A recent experimental study reported that carboxylized carbon nanotubes (CNTs) played an important role in regulating the α-ChT activity. In this study, parallel tempering Monte Carlo and molecular dynamics simulations were combined to elucidate the interactions between α-ChT and CNTs in relation to the CNT functional group density. The simulation results indicate that the adsorption and the driving force of α-ChT on different CNTs are contingent on the carboxyl density. Meanwhile, minor secondary structural changes are observed in adsorption processes. It is revealed that α-ChT interacts with pristine CNTs through hydrophobic forces and exhibits a non-competitive characteristic with the active site facing towards the solution; while it binds to carboxylized CNTs with the active pocket through a dominant electrostatic association, which causes enzymatic activity inhibition in a competitive-like mode. These findings are in line with experimental results, and well interpret the activity inhibition of α-ChT at the molecular level. Moreover, this study would shed light on the detailed mechanism of specific recognition and regulation of α-ChT by other functionalized nanomaterials.
authors: School of Chemistry and Chemical Engineering, Guangdong Provincial Key Lab for Green Chemical Product Technology, South China University of Technology, Guangzhou, 510640, P. R. China. jianzhou@scut.edu.cn.
authors: Daohui
authors: D
authors: Zhao
authors: School of Chemistry and Chemical Engineering, Guangdong Provincial Key Lab for Green Chemical Product Technology, South China University of Technology, Guangzhou, 510640, P. R. China. jianzhou@scut.edu.cn.
authors: Jian
authors: http://orcid.org/0000-0002-3033-7785
authors: J
authors: Zhou
mesh_terms: D002918:Chymotrypsin / Q000037:antagonists & inhibitors* / Q000737:chemistry; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D057927:Hydrophobic and Hydrophilic Interactions; D056004:Molecular Dynamics Simulation; D037742:Nanotubes, Carbon; D055672:Static Electricity
chemical_list: D004791:Enzyme Inhibitors; D037742:Nanotubes, Carbon; D002918:Chymotrypsin; C117608:alpha-chymotrypsin