Hybridization between fructose diphosphate aldolase subunits derived from diverse biological systems: anomolous hybridization behavior of some aldolase subunit types.

In the present studies we investigated the abilities of fructose diphosphate aldolase subunits derived from diverse biological sources to form stable heterotetramers with each other in vitro. Aldolase C subunits isolated from chicken brain readily "hybridized" with aldolase subunits derived from lobster muscle and wheat germ following reversible acid dissociation of mixtures of these enzymes; however, appreciable amounts of stable heterotetramers containing chicken C subunits and aldolase subunits isolated from two other invertebrates (Ascaris and squid) were not produced under the same conditions. In contrast to the situation with chicken C subunits, aldolase B subunits isolated from rat liver did not "hybridize" appreciably with lobster muscle or wheat germ aldolase subunits. The present observations are not consistent with the hypothesis that the abilities of different aldolase subunit types to form heterotetramers in vitro is governed solely by the evolutionary relationships which exist between the organisms from which the enzymes are derived.