BIOLOGY 2B03 Lecture Notes - Lecture 3: Heat Shock Protein, Protein Folding, Cold Shock Response
4 Nov 2018
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Document Summary
Molecular chaperones: bind to a short segment of a protein substrate and stabilize unfolded proteins this prevents these proteins from aggregating and being degraded. Chaperonins: form folding chambers into which all or part of an unfolded protein can be sequestered gives it time and an appropriate environment to fold properly. When do proteins unfold/misfold heat shock protein expression increases during aging (fruit flies, mice) and in mouse model systems of degenerative disorders (huntington"s and alzheimer"s diseases) Proteotoxic stresses these are stresses that increase the fraction of proteins that are in an unfolded state - due to many factors. Hsps protect against these stresses - when more favourable conditions return, the hsps are again down- regulated. Protein folding in the cell, internal and external stressors promote unfolding and misfiling. Anfinsen"s dogma in the cell: probability that such a polypeptide will fold correctly after removing the denaturant.
