Related papers: Crowding effects on the structural transitions in …
Biological molecules can form hydrogen bonds between nearby residues, leading to helical secondary structures. The associated reduction of configurational entropy leads to a temperature dependence of this effect: the "helix-coil…
We report circular dichroism measurements on the helix-coil transition of poly(L-glutamic acid) in solution with polyethylene glycol (PEG) as a crowding agent. Using small angle neutron scattering, PEG solutions have been characterized and…
Inspired by recent experiments on the effects of cytosolic crowders on the organization of bacterial chromosomes, we consider a "feather-boa" type model chromosome in the presence of non-additive crowders, encapsulated within a cylindrical…
Using molecular dynamics simulations, we investigate the aggregation behavior of neutral stiff (rod-like) and flexible polymer chains mediated by attractive crowders. Attractive crowders serve as bridging agents, inducing aggregation…
Macromolecular crowding can influence polymer shapes, which is important for understanding the thermodynamic stability of polymer solutions and the structure and function of biopolymers (proteins, RNA, DNA) under confinement. We explore the…
We explore the non-equilibrium dissipative dynamics of a system of identical charged particles trapped on a closed helix. The particles are subject to an external force accelerating them along the underlying structure. The effective…
By means of molecular dynamics simulations we investigate the formation of single-chain nanoparticles through intramolecular cross-linking of polymer chains, in the presence of their precursors acting as purely steric crowders in…
Most helix-coil transition theories can be characterized by a set of three parameters: energetic, describing the (free) energy cost of forming a helical state in one repeating unit; entropic, accounting for the decrease of entropy due to…
The thermodynamics of a homopolymeric chain with both Van der Waals and highly-directional hydrogen bond interaction is studied. The effect of hydrogen bonds is to reduce dramatically the entropy of low-lying states and to give raise to…
By means of extensive replica-exchange simulations of generic coarse-grained models for helical polymers, we systematically investigate the structural transitions into all possible helical phases for flexible and semiflexible elastic…
The phase behaviour of a single large semiflexible polymer immersed in a suspension of spherical particles is studied. All interactions are simple excluded volume interactions and the diameter of the spherical particles is an order of…
The looping of polymers such as DNA is a fundamental process in the molecular biology of living cells, whose interior is characterised by a high degree of molecular crowding. We here investigate in detail the looping dynamics of flexible…
The interior of cells is crowded thus making it important to assess the effects of macromolecules on the folding of proteins. Using the Self-Organized Polymer (SOP) model, which is a coarse-grained representation of polypeptide chains, we…
Using theoretical arguments and extensive Monte Carlo (MC) simulations of a coarse-grained three-dimensional off-lattice model of a \beta-hairpin, we demonstrate that the equilibrium critical force, $F_c$, needed to unfold the biopolymer…
Generic interactions e.g. the Coulomb or other long ranged radially symmetric repulsive interactions between monomers of bead-spring model of a semi-flexible polymer induce instabilities in a initially straight polymer chain to form long…
We study the effect of the crowded nature of the cellular cytoplasm on the translocation of a polymer through a pore in a membrane. By systematically treating the entropic penalty due to crowding, we show that the translocation dynamics are…
We derive an analytical pair potential of mean force for Brownian molecules in the liquid-state. Our approach accounts for many-particle correlations of crowding particles of the liquid, and for diffusive transport across the spatially…
Experiments show that macromolecular crowding modestly reduces the size of intrinsically disordered proteins (IDPs) even at volume fraction ($\phi$) similar to that in the cytosol whereas DNA undergoes a coil-to-globule transition at very…
Depletion-induced interactions between colloids in colloid-polymer mixtures depend in range and strength on size, shape, and concentration of depletants. Crowding by colloids in turn affects shapes of polymer coils, such as biopolymers in…
The coil-globule transition of hetero-polymer chains is studied here. By means of extensive Molecular Dynamics simulations, we show that the transition is directly linked to the complexity of the chain, which depends on the number of…