ABSTRACT
This chapter analyzes the effects of pressure on several types of protein reactions. High pressure affects protein structures at the secondary, tertiary and quaternary level. The high pressure stopped-flow technique was introduced by K. Heremans and further developed by C. Balny’s group and A. E. Merbach. The main problem for studying enzyme reactions under high pressure is the generally high reactivity of enzymes; the conversion of a substrate into a product starts immediately after mixing the enzyme with its substrate. If this mixing is done at atmospheric pressure, the time lap that is necessary to raise the pressure of the mixture precludes observation of early reaction stages. Carboxypeptidase from the thermophilic archaebacterion Sulfolobus solfataricus is another example of successful application of high pressure to study enzyme activity. In the absence of glycerol and beta-mercaptoethanol, this otherwise heat-stable enzyme undergoes thermal inactivation at 50°C.
