Multiple forms of fructose diphosphate aldolase in mammalian tissues.

Abstract
A new fructose diphosphate aldolase termed ''aldolase C'' was isolated from rabbit brain. Aldolase C can be distinguished from aldolase A and B by its catalytic properties, electrophoretic and chromatographic properties, and its immunochemical characteristics. Antibodies prepared against aldolase A and B do not cross-react with aldolase C. Five-membered aldolase sets including 3 hybrid forms are produced in vitro by reversible dissociation of a mixture of any 2 of the parental aldolases (A, B, or C). All 5 members of the A-C set can be produced on reversible dissociation of a single crystalline hybrid of the A-C set. Such hybrid forms are found in vivo in tissues which contain more than 1 parental aldolase type. The number of hybrid forms (3) can be easily reconciled with an enzyme composed of 4 similar subunits, but not with 3 chain models of the enzyme.