Porphyrin biosynthesis in rhodopseudomonas palustris-II. Evidence on the existence of a factor regulating aminolevulinate synthetase activity

• Autores: Viale, A.A.; De Xifra, E.A.W.; Del C. Batlle, A.M.
• Año de publicación: 1980
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Int. J. Biochem. 1980;12(5-6):729-733
• Materia: 5 aminolevulinate synthase; porphyrin; aerobic metabolism; article; biosynthesis; kinetics; metabolism; molecular weight; photosynthesis; Rhodopseudomonas; 5-Aminolevulinate Synthetase; Aerobiosis; Kinetics; Molecular Weight; Photosynthesis; Porphyrins; Rhodopseudomonas; Support, Non-U.S. Gov't
• Institución: Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales

1. 1. No changes in ALA-S activity were observed when different preparations of R. palustris were stored at 4°C for various periods of time. 2. 2. Mixing supernatants from pigmented and decoloured R. palustris cells, showed that the activity of ALA-S was several times higher than expected, suggesting the presence of an activator. 3. 3. Supernatants from photosynthetically and aerobically grown cells were heated and the effect of the protein-free supernatant was tested on both red and white supernatants. The heated supernatant from aerobic cells increased ALA-S when added to red and white preparations, but the heated red supernatant only activated red supernatant and had no action on the white cells enzyme. 4. 4. By gel filtration on Sephadex G-25 of cell free extracts from R. palustris either aerobically or anaerobically grown, a low molecular weight compound was separated, which added back to the homologeous enzyme enhanced its activity confirming the existence of one or two low-molecular weight and heat-stable factors which would act stimulating ALA-S activity. 5. 5. A scheme is proposed to explain the role of these factors on the control of ALA-S in R. palustris. © 1980.
Fil:Viale, A.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Del C. Batlle, A.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.