The Critical Point Of Interaction Between Macromolecules And Surfaces And Its Effects On The Transport Of Biopolymers

The critical point of interaction between macromolecules and surfaces is actually a critical point of the phase transition. The phenomenon of phase transition is a typical issue in physics and material study. Even though the problem has been studied for many years, it has not been understood thoroughly. The translocation of macromolecules through nanopores in nuclear and cellular membranes is commonly observed in processes of living. The electrophoresis is a standard method for the separation of macromolecules by length. How to improve the efficiency of separation is now a problem faced by researchers in the field of biological technology. In this paper, we study the critical point of interaction between macromolecules and surfaces, the critical phenomenon in translocation of biopolymer through membranes and the critical phenomenon of macromolecular transport in electrophoresis. It provides insight into the mechanisms of macromolecular transport in biological systems and also explores a new method in designing better separation techniques for biopolymers.The main innovations in this paper are:A. We relate the critical phenomenon of phase transition with the transport of biopolymers. Not only the static interaction between macromolecules and surfaces and the critical point of the interaction we study, but also we research the macromolecular transport near the critical point. The critical point obtained by dynamic method is consistent with that obtained by static method, so the dynamic method can be a new technique to study the property near the critical point.B. We enumerate exactly all configurations of tethered chains with different chain length, so we get the exact number of the configurations. By analyzing the dependence of the number of configurations on the chain length and the number of contacts, we get the function relationship which is extrapolated to longer chain. This is the first time that the dependence of the number of the configurations on the chain length and the number of contacts is expressed by a function.C. Taking account of the interaction between macromolecules and surfaces, we study the translocation of polymers through membranes. Analyzing the time of the translocation and the distribution of polymer monomers, we find there is a critical point while the time and the distribution change with the interaction energy changing.D. Many researchers have been committed themselves to improve the traditional gel electrophoresis, design and make better separation systems. A nanofluidic channel array device, consisting of many entropic traps, was designed and fabricated for the separation of long DNA molecules. We take account of the interaction between molecules and surfaces of the entropic traps system. We find that molecules moves quit differently because of the different interaction, so the molecules may be separated efficiently.