A reactor permitting injection and sampling for steady state studies of enzymatic reactions at high pressure: tests with aspartate transcarbamylase.
A high pressure reactor for steady state studies of enzymes is described. It allows injection, stirring, and sampling without release of the pressure (up to at least 400 MPa). Thus, either substrate or enzyme can be injected to initiate an enzyme-catalyzed reaction whose progress can then be followed by measurements on samples taken from the reactor. The dead time of sampling is 10-15 s, which allows reactions with pseudo-first-order rate constants smaller than about 1 min-1 to be monitored. It can be used for any enzymatic reaction; unlike previously described high pressure apparatus, it is not limited to the study of enzymes whose activity can be directly followed by spectrophotometry. The use and reliability of this reactor is demonstrated by tests with aspartate transcarbamylase. The activity of this enzyme is enhanced by pressures of the order of 120 MPa.
Laboratoire de Biologie Physico-chimique, Paris, France.
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D001221:Aspartate Carbamoyltransferase / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology; D006874:Hydrostatic Pressure; D007700:Kinetics; D013053:Spectrophotometry
D001221:Aspartate Carbamoyltransferase