title: Understanding interactions of functionalized nanoparticles with proteins: a case study on lactate dehydrogenase.
abstract: Nanomaterials in biological solutions are known to interact with proteins and have been documented to affect protein function, such as enzyme activity. Understanding the interactions of nanoparticles with biological components at the molecular level will allow for rational designs of nanomaterials for use in medical technologies. Here we present the first detailed molecular mechanics model of functionalized gold nanoparticle (NP) interacting with an enzyme (L-lactate dehydrogenase (LDH) enzyme). Molecular dynamics (MD) simulations of the response of LDH to the NP binding demonstrate that although atomic motions (dynamics) of the main chain exhibit only a minor response to the binding, the dynamics of side chains are significantly constrained in all four active sites that predict alteration in kinetic properties of the enzyme. It is also demonstrated that the 5 nm gold NPs cause a decrease in the maximal velocity of the enzyme reaction (V(max)) and a trend towards a reduced affinity (increased K(m)) for the β-NAD binding site, while pyruvate enzyme kinetics (K(m) and V(max)) are not significantly altered in the presence of the gold NPs. These results demonstrate that modeling of NP:protein interactions can be used to understand alterations in protein function.
authors.affiliation: National Institute for Nanotechnology, National Research Council of Canada, 11421 Saskatchewan Drive, EdmontonAlberta, T6G 2M9, Canada; Department of Electrical and Computer Engineering, University of Alberta, 9107-116 Street, Edmonton, Alberta, T6G 2V4, Canada.
authors.forename: Oliver
authors.initials: O
authors.lastname: Stueker
authors.forename: Van A
authors.initials: VA
authors.lastname: Ortega
authors.forename: Greg G
authors.initials: GG
authors.lastname: Goss
authors.forename: Maria
authors.initials: M
authors.lastname: Stepanova
mesh_terms: D003198:Computer Simulation; D004789:Enzyme Activation; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000648:ultrastructure; D006046:Gold / Q000737:chemistry*; D007770:L-Lactate Dehydrogenase / Q000737:chemistry* / Q000648:ultrastructure; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D058726:Nanoconjugates / Q000737:chemistry / Q000648:ultrastructure; D010316:Particle Size; D011485:Protein Binding
chemical_list: D004800:Enzymes, Immobilized; D058726:Nanoconjugates; D006046:Gold; D007770:L-Lactate Dehydrogenase
keywords: enzyme function; molecular simulation; nanomaterials; nanomedicine; toxicology