Evidence for a pH-dependent isomerization of Clostridium oroticum dihydroorotase.
Analytical gel permeation chromatography on both Sephadex and polyacrylamide columns shows that Clostridium oroticum dihydroorotase (L-5,6-dihydroorotate amidohydrolase, EC 3.5.2.3) undergoes a large decrease in molecular size when the pH is decreased from 8 to 6. The Stokes radius decreases from about 40 A to 36 A. Neither the molecular size nor kinetic properties are dependent on protein concentration. Thus, the decreased molecular size reflects a pH dependent isomerization of the enzyme.
Bidigare
R R
RR
Sander
E G
EG
Pettigrew
D W
DW
D000581:Amidohydrolases / Q000378:metabolism*; D002850:Chromatography, Gel; D003013:Clostridium / Q000201:enzymology*; D004080:Dihydroorotase / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D007700:Kinetics
D000581:Amidohydrolases; D004080:Dihydroorotase