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Updated: Jul 29, 2026

Direct Detection of the Acetate-forming Activity of the Enzyme Acetate Kinase
Published on: December 19, 2011
Kinetics of structure and activity changes during the allosteric transition of aspartate transcarbamylase
H Kihara1, E Takahashi-Ushijima, Y Amemiya
1Department of Physics, Jichi Medical School, Tochigi-ken, Japan.
Abstract:
For the first time, the structural change associated with an allosteric transition has been monitored by X-ray solution scattering. The kinetics of the quaternary structure change of aspartate transcarbamylase were first slowed by using acetyl phosphate instead of carbamyl phosphate, and by the presence of 10% or 30% ethylene glycol. At 6.5 degrees C, the quaternary structure change was found to have a time constant of about 11 seconds. This appears to be larger than that obtained for the switching of homotropic co-operativity, measured by chemical quench under the same conditions.
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