Alpha gamma-enolase in the rat: ontogeny and tissue distribution.

The rat brain enolases are dimers composed of alpha and gamma subunits. At pH 8.6 alpha gamma-enolase seemed to be stable, and no evidence was found for the possible formation of alpha gamma-enolase from alpha alpha-enolase and gamma gamma-enolase in the course of rat brain homogenization. During ontogeny of the rat forebrain, alpha gamma-enolase was formed before gamma gamma-enolase. The half-maximal specific concentrations were reached at postnatal days 14 and 23, respectively. The distribution of alpha gamma- and gamma gamma-enolase in various rat brain areas was also investigated. In all areas both forms were present. In neuroendocrine tissues alpha gamma-enolase was present at much higher concentration than gamma gamma-enolase. The ratio between gamma gamma-enolase and alpha gamma-enolase may be indicative of the degree of neuronal maturation, a conclusion further substantiated by the high ratio observed in cerebellum and the low ratio observed in olfactory bulbs, both compared with the ratio in forebrain.