相关论文: Stability of DNA molecule in conical shaped cellul…
A three dimensional mesoscopic model is applied to study the properties of short DNA chains in a confining environment. The cylindrical channel is represented by a hard-wall repulsive potential incorporated in the system Hamiltonian. The…
Living cells provide a fluctuating, out-of-equilibrium environment in which genes must coordinate cellular function. DNA looping, which is a common means of regulating transcription, is very much a stochastic process; the loops arise from…
A theory of the unzipping of double-stranded (ds) DNA is presented, and is compared to recent micromanipulation experiments. It is shown that the interactions which stabilize the double helix and the elastic rigidity of single strands (ss)…
The denaturation of double-stranded DNA as function of force and temperature is discussed. At room temperature, sequence heterogeneity dominates the physics of single molecule force-extension curves starting about 7 piconewtons of below a…
The equilibrium statistical properties of DNA denaturation bubbles are examined in detail within the framework of the Peyrard-Bishop-Dauxois model. Bubble formation in homogeneous DNA is found to depend crucially on the presence of…
Topology affects physical and biological properties of DNA and impacts fundamental cellular processes, such as gene expression, genome replication, chromosome structure and segregation. In all organisms DNA topology is carefully modulated…
We studied the unzipping kinetics of single molecules of double-stranded DNA by pulling one of their two strands through a narrow protein pore. PCR analysis yielded the first direct proof of DNA unzipping in such a system. The time to unzip…
The double-helical structure of DNA results from canonical base pairing and stacking interactions. However, variations from steady-state conformations result from mechanical perturbations in cells. These different topologies have…
It had been proposed that overstretching double stranded DNA from the 5-5 ends will produce a new fiber form of dsDNA that is narrower than the S form that has been suggested to result when the dsDNA is overstretched from the 3-3 ends. We…
The present work is devoted to the study of the thermostability of native DNA during binding to TiO$_{2}$ nanoparticles (NPs) at various concentrations under conditions close to physiological (0.1 M Na $^+$, pH 7) using thermal denaturation…
The closure of long equilibrated denaturation bubbles in DNA is studied using Brownian dynamics simulations. A minimal mesoscopic model is used where the double-helix is made of two interacting bead-spring freely rotating strands, with a…
A Rayleigh B\'enard instability study using the energy conserving dissipative particle dynamics method is presented here for the first time. The simulation is performed on an ideal dissipative particle dynamics fluid in a three dimensional…
Encapsulation of dsDNA fragments (contour length 54 nm) by the cationic diblock copolymer poly(butadiene-b-N-methyl 4-vinyl pyridinium) [PBd-b-P4VPQ] has been studied with phase contrast, polarized light, and fluorescence microscopy, as…
In this paper we consider a physical system in which two DNA molecules braid about each other. The distance between the two molecular ends, on either side of the braid, is held at a distance much larger than supercoiling radius of the…
Multistep denaturation in a short circular DNA molecule is analyzed by a mesoscopic Hamiltonian model which accounts for the helicoidal geometry. Computation of melting profiles by the path integral method suggests that stacking…
The ubiquitous biomacromolecule DNA has an axial rigidity persistence length of ~50 nm, driven by its elegant double helical structure. While double and multiple helix structures appear widely in nature, only rarely are these found in…
We introduce and numerically study a model designed to mimic the bulk behavior of a system composed of single-stranded DNA dendrimers. Complementarity of the base sequences of different strands results in the formation of strong cooperative…
We propose a model for the fluctuation dynamics of the local denaturation zones (bubbles) in double-stranded DNA. In our formulation, the DNA strand is model as a one dimensional Rouse chain confined at both the ends. The bubble is formed…
We present a simple model which describes elastic response of single-stranded DNA (ssDNA) to stretching, including the regime of very high force (up to 1000 pN). ssDNA is modelled as a discreet persistent chain, whose ground state is a…
We predict a novel temperature-driven phase transition of DNA below the melting transition. The additional, intermediate phase exists for repetitive sequences, when the two strands have different lengths. In this phase, the excess bases of…