At what temperature can enzymes maintain their catalytic activity?
It was shown by the combination of thermogravimetric analysis and Karl Fisher titrations that temperatures in excess of 200 degrees C are required to remove tightly bound water from proteins. The heating of enzymes to this temperature caused no cleavage of the polypeptide chains and very little, if any, chemical degradation of particular amino acid residues as judged by electrophoretic and amino acid analysis respectively. It was hypothesised that those enzymes that require very little water for their catalytic activity, should remain active at such elevated temperatures provided that they can be stabilised against thermodenaturation. This conclusion has been verified by the observation that immobilised Candida antarctica lipase catalysed transesterification of octadecanol with palmityl stearate at 130 degrees C for a considerable period of time.
Turner
NA
Institute of Food Research, Norwich Research Park, Colney, NR4 7UA, Norwich, UK
Vulfson
EN