TRH (Thyrotropin Releasing Hormone) Influences the Pterin Cofactor- and Time-Dependent Instabilities of Rat Raphe Tryptophan Hydroxylase Activity Assessed under Far-From-Equilibrium Conditions

摘要

This series of experiments demonstrates the action of a tri-peptide, thyrotropic releasing hormone (TRH) on the far-from-equilibrium kinetics of rat raphe tryptophan hydroxylase as model of how such ligand-protein interactions change the patterns of time-dependent instabilities rather than amount of product produced per unit time. Our somewhat controversial position, that there are no rates in the form of linear differential equations of the classical kinetic type, but rather global nonlinear dynamical patterns of behavior modeled by maps and flows on low dimensional manifolds is seen here in the form of power law spectra, autocorrelation graphs, and Hausdorf dimensions on real data. The peptide induced changes seen previously using ion ligands (lithium versus calcium) and cholinergic antidepressant drugs. Transitions from a high entropy, white noise pattern to that of slow coherence addresses the issue outlined above concerning irreversibility. A control group of studies indicates these effects are unrelated to facilitation or inhibition of thermally induced denaturation.