Intracellular Localization of Glycolate Dehydrogenase in a Blue-Green Alga 1

AUTOR(ES)

Grodzinski, Bernard

RESUMO

Glycolate dehydrogenase activity was detected in cell-free extracts of Oscillatoria sp. prepared by osmotic lysis of spheroplasts in 0.05 m potassium phosphate buffer, pH 7.5, containing 0.3 m mannitol. Most of the enzyme activity was found in a particulate fraction and localized in the photosynthetic lamellae after centrifugation in a discontinuous sucrose density gradient. Enzyme activity was detected in this fraction both in the presence and absence of the artificial electron acceptor 2,6-dichlorophenolindophenol (DPIP) and a low rate of O2 uptake was detected in this lamellar fraction. Activity was lost from the lamellar fraction by repeated washing or by treatment with 0.005% Triton X-100 and the solubilized enzyme activity was DPIP-dependent. The data indicate that both glycolate dehydrogenase and its natural electron acceptor are bound to the photosynthetic lamellae in vivo. In contrast, catalase activity was found in the soluble cytoplasmic fraction.

Documentos Relacionados

• Protochlorophyll(ide) in a Blue-Green Alga
• Purification and Characterization of Glucose Dehydrogenase from a Heterotrophically Grown Blue-Green Alga 1
• Phosphorus-Limited Growth of a Green Alga and a Blue-Green Alga
• Phycobilisomes from a Blue-Green Alga Nostoc Species
• Factors influencing dark nitrogen fixation in a blue-green alga.