Abstract

Proteins are biopolymers built up from 20 different amino acids. Their diversity derives from the different combinations of the amino acids that form the sequence. The function of a protein depends on its unique three-dimensional structure, which is itself determined by the amino acid sequence. The principal forces that drive proteins to their folded structure are the hydrophobic effect and backbone hydrogen bonding. The latter gives rise to the two elements of secondary structure, -helix and -sheet, commonly observed in proteins. The number of ways that these structures can pack is finite, giving rise to a limited number of folding motifs that recur in proteins of even unrelated structure. The function of proteins is carried out by a few residues in an active site which interacts with other molecules. Prediction of protein structure from its amino acid sequence is an active area of research. Different approaches include energy minimization, comparative modeling, and inverse protein folding. Progress in molecular biology and molecular modeling have made the study of the function and design of proteins a reality. With the sequencing of the human genome, much research is being done in the area of comparative genomics to understand the molecular basis of the diseased state and “personalized” medicine. Systems biology is another area which has drawn a lot of attention.