Proteins and Protein Structure

Abstract

Proteins such as enzymes, channels, signaling molecules and adaptors carry out important functions in living organisms. Fibrous and globularGlobularproteins comprise two large groups. Long stretches of coiled coilCoiled coilα-helices in fibers and fibrils, triple helices of collagenCollagen, and globular hemeHemebinding subunits of hemoglobin give us main representatives and show how diverse these molecules are. Protein polypeptidePolypeptidechain exhibits left-handed and right handed, parallel and antiparallel arrangements of secondary structure elements such as alpha, 310310, polyproline, gamma and pi helices, strands and turns. This chapter describes structural principles of protein molecule, its conformationConformationand relationships between primary, secondary, tertiary, and quaternary structure.