Studies on the Mechanism of Action of the Histone Kinase Dependent on Adenosine 3',5'-Monophosphate. Investigation of Protein-Protein Interaction by Electron Spin-Resonance Spectroscopy and Stopped-Flow Methods

Publisher Website
Google Scholar
Abstract
The interaction of the [pig brain] cAMP-dependent protein kinase catalytic subunit with its protein substrate, histone H1, was studied. The H1 molecule was specifically converted into the aminotyrosine-72 derivative. Fluorescent and spin labels were introduced into this residue. The changes in the ESR and fluorescence spectra of respective derivatives were observed upon the interaction of the latter with catalytic subunit, thus enabling some kinetic and equilibrium parameters of this process to be determined. Stopped-flow investigation of the transient phase of the binding reaction indicates that the kinetic curve is described by a 3-exponential function. The rate of protein-protein interaction is close to the rate of phosphate transfer from phosphoenzyme intermediate to protein substrate.