|MadSci Network: Chemistry|
PEG is usually not used to protect the tertiary or quaternary structure of a protein. That is, PEG is usually not used to stabilize a protein from degradation. PEG is a polymer of differing length that is usually used to study the structure of a protein or for separation, such as in density gradient centrifugation (isopycnic centrifugation). Would PEG actually prevent degradation, that would depend on conditions independent of the PEG (such as temperature, oxidation level...). Ammonium sulfate or glycerol is usually used to stabilize proteins. Salt has a stabilizing effect on the protein up to a certain concentration, depending on the protein and salt. PEG could stablize a protein, but again, other conditions would need to be favorable as well.
hope this helps, and it isn't too late...:-)
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