BIOLOGY 2B03 Lecture Notes - Lecture 2: Groes, Groel, Protein Folding
10 Sep 2016
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Document Summary
Mechanisms used by molecular chaperones & chaperonin complexes. Correcting misfolding: chaperones (most proteins fold rapidly into native conformation) Incompletely folded proteins can be assisted by chaperone proteins & chaperonin complexes. If protein ultimately can"t be folded, aggregates can form (which are detrimental to cell) Cell removes these proteins via degradation in proteasome. Both monomeric molecular chaperones & multimeric chaperonin complexes help proteins to fold by preventing formation of incorrect folding within the molecule or of inappropriate associations with other proteins/amino acid residues. Seen in all organisms & subcellular compartments where protein folding occurs. Molecular chaperones: monomeric proteins; bind to hydrophobic amino acid residues on polypeptide; prevent protein from forming incorrect folds due to hydrophobic interactions in aqueous environment within protein/other proteins. Expressed all the time, but at high levels under conditions of stress. When cell exposed to high temperatures, cell responds by making heat shock proteins to refold various proteins. Found in cytosol & mitochondria of eukaryotic cells.
