BIOLOGY 2B03 Lecture Notes - Lecture 2: Peptide, Protein Structure, Groel
7 Feb 2021
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Protein folding: proteins will fold in an attempt to move towards a lower energy state. Intracellular environment is very crowded, many things can influence protein folding. Internal and external stressors promote unfolding and refolding. Anfinsen dogma in the cell: the probability that such a polypeptide will fold correctly after removing the denaturant increases at low protein concentration (which limits interpolypeptide interactions) and low temperatures (which attenuates hydrophobic interactions). (jaenicke 1991, but! The cell is a crowded and warm environment! Competition between protein folding and aggregation: all proteins try to fold into low energy thermodynamically stable state, proteins are always being torn between folded and misfolded, and aggregated states. Monomeric molecular chaperones: bind to a short segment of a protein substrate and stabilize unfolded proteins, thereby preventing these proteins from aggregating and being degraded. Multimeric chaperonins: form folding chambers into which all or part of an unfolded protein can be sequestered, giving it time and an appropriate environment to fold properly.
