Principles of Protein Structural Organization - H. Schultz 1982

Interactions Determining Protein Structure

Non-covalent interactions were discovered by Structure/103.html">Van der Waals (1873) in his attempt to explain the deviation of real gas behavior from the ideal gas law. Interactions between non-bonded atoms are of paramount importance for biological organisms; specifically, they are responsible for the spontaneous folding of polypeptide and nucleic acid chains, as well as the spontaneous formation of membranes. They drive the recognition of complementary molecular surfaces (the "lock-and-key" mechanism) [44].

The various types of non-covalent interactions are listed in Table 3.1; their absolute bond energy is one to three orders of magnitude smaller than that of covalent bonds. The magnitude of non-covalent interactions is both difficult to measure and difficult to calculate. Furthermore, the surrounding environment makes a significant entropic contribution to Protein Stabilization. Therefore, the system must be considered as a whole, taking into account both the protein and the solvent.

Class="center">Table 3.1 Types of interactions important for protein structuresa

a In calculations of electrostatic interaction energy, the dielectric constant is assumed to be 4.