Abstract:
Proteins form the very basis of life, the term protein is derived from the Greek word proteios,
which means standing in front. Proteins regulate a variety of activities in all living organisms,
from replication of DNA to transport of oxygen across the body. Proteins are responsible for
regulating cellular machinery and consequently the phenotype of an organism. Proteins
accomplish their task by three-dimensional tertiary and quaternary interactions with various
substrates such as DNA, RNA and other proteins. By understanding the structure of the
protein, we can probe for its function and potentially apply the new knowledge to various
genome and proteome projects, such as mapping the functions of proteins in metabolic
pathways and deducing evolutionary relationships and proteome network which is useful in
system biology. Peptides1 are short fragments of proteins consists of amino acids linked by
amide bonds.2 Peptides can be normally differentiated from proteins by the number of amino
acids present in a given chain. Generally a peptide constitutes a minimum of two amino acid
residues or a maximum of 50 amino acid residues per chain. Smallest known peptide is a
dipeptide followed by tripeptide, tetrapeptide etc.
