Theory and practice of the analytical centrifugation of an active substrate–enzyme complex

Abstract

Abstract The active enzyme centrifugal‐ion (AEC) method presented here permits the hydrodynamic study of active enzyme – substrate ( s ) complexes in solutions containing micro‐gram amounts of the studied enzyme, even if the enzyme preparation is very impure. The AEC method can he used only when the specific enzymatie reaction can be measured directly in a spectrophotometer. The general equations relevant to the method and their solutions are presented in detail. Their use requires some numerical calculations. A practical summary of the AEC method is given, and the precision of the measured values of the sedimentation and diffusion coefficients is discussed.