Principles of Protein Structure - G. Schultz 1982

Protein Evolution
Protein Specialization
Amino Acid Substitutions as Experiments Conducted by Nature

Mutant Proteins can be employed to decipher structural principles. All fixed protein Mutations can be viewed as nature's experiments, indicating which variations have little effect on protein stability and folding dynamics. On the other hand, random and apparently non-fixed mutations, such as those in abnormal Hemoglobin, provide Examples of variations that significantly reduce protein structural stability. Both Selection/21.html">Types of mutations can be used to refine our understanding of non-covalent forces in proteins. For this purpose, energy Minimization Procedures for wild-type and mutant polypeptide chains can be applied based on known three-dimensional structures [501]. The energy differences and geometric deviations determined in this manner can be compared with experimental data obtained from thermodynamic measurements [413, 417] and high-resolution X-ray crystallographic studies, respectively. Similar comparisons can be made using chain-folding simulations (Sec. 8.6), which yield additional insights into certain aspects of the folding process.