An Immunochemical Study of Structural and Evolutionary Relationships among Molluscan Octopine Dehydrogenases

Abstract

Antisera produced against octopine dehydrogenases isolated from a gastropod and a cephalopod were used to investigate structural and evolutionary relationships of this enzyme in a range of mollusks. Antisera against octopine dehydrogenase of the blue-ringed octopus Hapalochlaena maculosa was most effective in inhibiting the enzyme from other octopods, followed by the enzymes of squids and cuttlefishes. Limited inhibition also occurred with octopine dehydrogenase of Nautilus pompilius, a representative of the most ancient group of living cephalopods. This antisera did not inhibit octopine dehydrogenases ofgastropods or bivalves. Antisera against the enzyme of the gastropod Strombus luhuanus inhibited octopine dehydrogenases from other genera of the family Strombidae, but did not inhibit the enzyme from other families of gastropods or the enzymes from cephalopods or bivalves. It is concluded that the octopine dehydrogenases of cephalopods possess structural similarities and have diverged from a common ancestral gene. The structural and evolutionary relationships among gastropod octopine dehydrogenases and the relationships among octopine dehydrogenases from different molluscan classes remain unresolved.