Methods and models for the study of structure, cold denaturation and aggregation of proteins

Abstract

Proteins are the building blocks of the living cell. They perform a wide range of functions like enzymatic catalysis, gene regulations, signal transmission etc., and form an important structural component of cells and tissues. The diversity of their roles demands a diversity of structures, but each individual protein has a well defined three dimensional structure. Proteins are complex polymers composed of amino acids. Amino acids are organic molecules and have different properties. There are twenty different amino acids. The sequence of amino acids is unique for each protein. A single protein may contain one type of amino acid (homopolymer) e.g. actin, or different types of amino acids (heteropolymer). An amino acid consists of a backbone and a side group. The side group of one amino acid is different from that of another amino acid. The number of atoms in a side group of amino acids varies from 1 to 10 (excluding hydrogen atoms). Hence the number of atoms in a protein depends on its composition and length. Since the degrees of freedom of a system is proportional to the number of atoms, having a larger number of atoms increases the complexity of a protein.