Entropy driven key-lock assembly

Abstract

The effective interaction between a sphere with an open cavity (lock) and a spherical macroparticle (key), both immersed in a hard sphere fluid, is studied by means of Monte Carlo simulations. As a result, a 2d map of the key-lock effective interaction potential is constructed, which leads to the proposal of a self-assembling mechanism: there exists trajectories through which the key-lock pair could assemble avoiding trespassing potential barriers. Hence, solely the entropic contribution can induce their self-assembling even in the absence of attractive forces. This study points out the solvent contribution within the underlying mechanisms of substrate-protein assembly/disassembly processes, which are important steps of the enzyme catalysis and protein mediated transport.

Protein Folding, Binding and Energy Landscape: A Synthesis

“…Nevertheless, the types and strength of the bonds formed between the protein and ligand contribute to the binding affinity. Our speculation is in line with the recent study by Odriozola and coworkers (Odriozola et al, 2008), who showed that the key-lock assembly is solely driven by the entropic contribution even in the absence of attractive forces, pointing out the importance of solvent contribution in the underlying mechanisms of substrate-protein assembly processes.…”

Depletion-induced biaxial nematic states of boardlike particles

“…Since then, the concepts related to depletion have been widely applied to various scientific fields [34]: in biology by interpreting phenomena like macromolecular crowding [35] and protein crystallization [36]; in nanotechnology through e.g. the development of self-assembly processes as key-lock structures [37,38]; in condensed matter physics, furnishing answers to fundamental problems like the condition for gas-liquid phase separation [39], the kinetics of crystallization [40,41] and the nature of glassy states [42]. More recently, the liquid crystal phase behavior of non-spherical colloids, typically rods [43][44][45][46][47][48] and plates [49][50][51][52], in presence of a depletant has also been addressed.…”

Sterically stabilized lock and key colloids: A self-consistent field theory study

“…[4][5][6][7][8] In the present work, we assume cylindrical shape both for the key particle and for the lock cavity. In particular, the key particle is assumed to be a cylinder of radius R k and height H, while the lock cavity is characterized by radius R l and depth D. The conditions R k = R l and H = D correspond to the perfect size matching between lock and key.…”

“…[2,3] As such, these model systems have recently received substantial attention both experimentally [2,3] and theoretically. [4][5][6][7][8] In a recent experimental study, [2] an efficient method has been developed to produce colloidal lock particles containing a spherically shaped cavity. The interaction between these lock particles and complementary spherical key particles is comprised of two major contributions: Coulomb repulsion arising due to charge stabilization, and depletion attraction [9] due to the presence of the polymeric depletants in solution.…”

“…[2] On the theoretical side, key-lock interactions in colloidal systems have been studied using integral equation theory, [4], density functional theory, [6] and molecular simulation techniques. [7] Very recently, a highly efficient hybrid approach to study key-lock model systems (among other multidimensional problems) has been developed, which combines Monte Carlo simulation for obtaining microscopic configurations of the depletant particles and density functional theory for calculating the free energy. [8] All these previous studies employed microscopic models based exclusively on hard-sphere excluded volume interactions, whereby the depletion attraction between lock and key particles is driven by the entropic solvent contribution.…”