BIOL 301 Chapter Notes - Chapter 4: Ramachandran Plot, Peptide Bond, Relative Permittivity
Document Summary
Spatial arrangement of atoms in a protein or any part of a proteins is called its conformation. Change in conformation could occur by rotation of single bonds. One is generally predominant under biological conditions. Proteins in any of their functional, folded conformations - called native proteins. A protein"s conformation is stabilized largely by weak interactions. Stability- tendency to maintain a native conformation. Need chemical interactions to counteract effects of entropy (wanting to be unfolded state) to stabilize native conformation. Disulfide covalent bonds, weak noncovalent interactions (hydrogen bonds and hydrophobic and ionic interactions) Outside of cell- environment more oxidizing, inside cell more reducing. Net stability contributed by a given hydrogen bond, or the difference in free energies of the folded and unfolded states, may be close to zero (so why else would native conformation be favored??) When water surrounds hydrophobic molecule optimal arrangement of hydrogen bonds results in highly structured shell, or solvation later.
