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Determination of the Glycogen Content in Cyanobacteria
Published on: July 17, 2017
Ribulose Diphosphate Carboxylase from Autotrophic Euglena gracilis
H Rabinowitz1, A Reisfeld, D Sagher
1Department of Plant Genetics, Weizmann Institute of Science, Rehovot, Israel.
Plant Physiology
|September 1, 1975
Summary
Ribulose 1,5-diphosphate carboxylase (RUDPcase) from Euglena gracilis was purified and characterized. This key photosynthetic enzyme shows structural similarities to higher plants, suggesting evolutionary links.
Area of Science:
- Biochemistry
- Molecular Biology
- Photosynthesis Research
Background:
- Ribulose 1,5-diphosphate carboxylase (RUDPcase) is crucial for carbon fixation in autotrophs.
- Understanding RUDPcase structure and evolution provides insights into photosynthetic efficiency.
Purpose of the Study:
- To purify and characterize RUDPcase from autotrophically grown Euglena gracilis.
- To investigate the phylogenetic relationship between Euglena RUDPcase and that of higher plants.
Main Methods:
- Enzyme purification using analytical ultracentrifugation and electrophoresis.
- Subunit analysis via denaturation and amino acid composition determination.
- Immunochemical reactions and amino acid analyses for phylogenetic comparison.
Main Results:
- Purified Euglena RUDPcase has a high molecular weight (>500,000 daltons) and dissociates into large (59,000 Da) and small (12,000 Da) subunits.
- The enzyme constitutes a significant portion of cellular protein in autotrophic Euglena.
- Structural similarities were observed between Euglena and higher plant RUDPcase, with notable differences in small subunits.
Conclusions:
- Euglena gracilis RUDPcase shares structural and evolutionary relationships with higher plant carboxylases.
- The large subunit shows closer amino acid correspondence between Euglena and lettuce than the small subunit.
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