Serological comparison of ribulose-1,5-diphosphate carboxylase from Euglena gracilis, chlorella fusca and several blue-green algae

Abstract

An antiserum prepared to the ribulose-1,5-diphosphate carboxylase (RuDPCase) of Euglena gracilis has been tested by double immuno-diffusion against the pure homologous enzyme and against extracts from E. gracilis, Chlorella fusca and four species of blue-green algae. Single precipitin bands were formed in all cases. partial immunological identity was established between the E. gracilis and C. fusca enzymes. The precipitin bands produced by the blue-green algae were all mutually identical but only partially identical with both eukaryotic algal enzymes. The enzymatic activities of the RuDPCase purified from E. gracilis and C. fusca were inhibited by the antiserum to the Euglena enzyme, the same inhibition—antibody titre relationship occurring. The antiserum also inhibited ribulose diphosphate carboxylase activity in all blue-green algal extracts tested.