Question

explain how works 1. Electric forces in biomolecules DNA and protein. 2. Electric potential and hearth dynamics.

Answer 1

1. Electrostatics plays an important role in the modern biology. The important molecules of life like proteins, nucleic acid and amino acids are electrically charged. DNA is the highly charged molecule with about 2qe. The electrostatic force holds the DNA molecules together and give the structure and strength to the molecules. The base pairs in the DNA (A,T,G and C) always pair in a specific manner to pass the correct genetic information.

Since the Coulomb force drops with the distance (F∝1/r2). The distance between the base pair is supposed o be small enough that the electrostatic force is sufficient to hold them together.

The electrostatic force also provide stability to the protein molecules. The ionic bonds form as the opposite electric charge on the amino acids juxtaposed in the hydrophobic core of the protein. This has been seen that ionic bonding is rare in the interior as most charged amino acids fall on the surface of protein. The electrically charged amino acids on the protein surface promote the folding by interacting with the water solvents. The polar molecule of the water form shells around the charged surface residue side chain. This process help in stabilize and solubilize the protein.

2. The electrostatic potential is a powerful tool for the study of molecular association and in rational drug design. Electrostatic potential around the DNA is usually obtained by the non-linear Poisson-Boltzmann (PB) equation. The high charge density of the nucleic acids renders invalid the standard assumption that electrical potential are much less then kT. The electrostatic potential in the minor groove is entirely negative. The G-C minor groove has large negative potential due to the contribution of phosphate oxygen.

This has been seen that the DNA-binding proteins will most likely have a pockets of positive charges. The electric potential of the protein determine the binding of DNA molecule.

The role of DNA as both a structural scaffold and the carrier of sequence information hugely influence its interactions with DNA-binding proteins. DNA is highly dynamic enwrapping layers of complexity. DNA contributes to the processes that tells how protein-DNA interactions form.