Life on a Knife Edge: Tipping the Balance between folding and Aggregation - Essay Example

ctions by folding into one or more conformations and some of the important interactions that come into play are ionic interactions, hydrogen bonding, Van der Waals’ forces and hydrophobic packing (Berg, 2002). The three dimensional structures of proteins aid in delineating protein functions at a molecular level and the structure of proteins are determined usually with X ray crystallography, NMR spectroscopy etc. Some structural features of proteins would be necessary to perform certain biochemical functions although multifunctional and structural proteins may have higher number of residues than the average of 300 residues.

Large aggregates are formed as a result of folding from protein subunits and actin molecules also assemble into actin filaments. The protein structure has four distinct features including amino acid sequence of peptide chains as seen in a primary structure, secondary structures which are regular sub structures, such as strands of beta sheet, tertiary structure as seen in the three dimensional structure of a single protein molecule and quaternary structure which represents a complex of polypeptide chains and protein molecules (Copley, 1997; Berg, 2002).

Proteins tend to transition between structures to perform the biological functions and this would be known as conformational changes. The primary structure of proteins with amino acid sequences would be held together by covalent peptide bonds and the extremities of the amino acid chains are known as carboxy terminus (C – terminus) and amino terminus ( N –terminus). The secondary structures are defined by their patterns of hydrogen bonds between the peptide groups although these bonds are generally not too stable except in conditions when the water concentration is low as in molten globule or fully folded states (Urbanc et al, 2006).

The non specific interactions and propensities of amino acids would lead to the formation of molten globules. The tertiary structure shows structurally