Operon Hypothesis: New Evidence from the ‘Constant Proportion’ Group of the Embden–Meyerhof Pathway

Abstract

A NUMBER of examples have now been reported in which a group of enzymes is synthesized in such a manner that the relative activity of each of the enzymes within, the group is constant. An important example of this is the ‘constant-proportion’ group in the Embden–Meyerhof pathway, which has been extensively investigated by Vogell et al.¹ and by Pette et al.². These workers examined a wide range of materials, extending from baker's yeast to various mammalian tissues, and found that the activity of the five enzymes, triosephosphate isomerase to enolase, formed a pattern which is quite reproducible. They suggest that this indicates a “co-ordinate control of enzyme synthesis” by the cell at the molecular level, a subject which has been the focal point of much recent attention.