TERTIARY STRUCTURE OF PROTEINS

INTRODUCTION:  Secondary structure denotes the configurational relationship between residues which are about 3-4 amino acids apart; or secondary level defines the organization at immediate vicinity of amino acids. The tertiary structure denotes three dimensional structure of the whole protein. The tertiary structure defines the steric relationship of amino acids which are far apart from each other in the linear sequence, but are close in the three-dimensional aspect.

STABILITY OF THE TERTIARY STRUCTURE: The tertiary structure is maintained by non-covalent interactions such as hydrophobic bonds, electrostatic bonds and van der Waals forces. The tertiary structure acquired by native protein is always thermodynamically most stable.

DOMAIN:  This is the term used to denote a compact globular functional unit of a protein. A domain is a relatively independent region of the protein, and may represent a functional unit. The domains are usually connected with relatively flexible areas of protein. To give an example, Phenyl alanine hydroxylase enzyme contains 3 domains, one regulatory, one catalytic and one protein-protein interaction domains.

 

RELATED;

1.  BIOCHEMISTRY OF PROTEINS

2. BIOCHEMISTRY OF BONDS

3. IMMUNOGLOBULINES

4. ENZYMES

REFERENCES