Enolase isoenzymes. III. Chromatographic and immunological characteristics of rat brain enolase.

1. The chromatography of rat brain enolase (2-phospho-D-glycerate hydrolyase, EC 4.2.1.11) reveals three distinet components. One of these appears to be isoenzyme 1 (alpha alpha) but isoenzymes 2 (alpha beta) and 3 (beta beta) are absent. 2. The most acidic form of brain enolase was partially purified and an antiserum raised against it in the chicken. 3. a combination of chromatographic and immunological studies showed that a third type of subunit (gamma) is present in the brain giving rise to two further isoenzymes (alpha gamma and gamma gamma). 4. Developmental studies on the brain enzyme show an increase in total enolase activity from foetal life to maturity and a concurrent rise in the proportion of brain specific dimers. 5. It is therefore concluded that there are three genetic loci alpha, beta and gamma, coding for the enolase isoenzymes of rat tissues.