Sustained sinusoidal oscillations of reduced pyridine nucleotide in a cell-free extract of Saccharomyces carlsbergensis.

Abstract

A train of over 90 sinusoidal oscillations of the DPNH level was observed in a cell-free extract of S. carlspergensis supplemented with a single addition of trehalose. Such sustained oscillations frequently had an average damping factor of approximately 1.01 and an average Q value in excess of 100. Trehalose was also the primary substrate for the spontaneous oscillations in the nonsupplemented extract. The observation of doubly periodic oscillations and oscillations showing beat frequencies indicates that gly-colytic control can be exerted by at least 2 mechanisms in this system. These observations rule out certain mechanisms for the oscillations, and suggest that sustained oscillations may exist in vivo where they could function as the basic regulators of biological clocks.