What question did this study set out to answer?

To determine and compare the kinetic constants Km(CO2) and Km(RuBP) of ribulose-1,5-bisphosphate carboxylase across taxonomically diverse terrestrial and aquatic plant groups.

June 1, 1981PLANT PHYSIOLOGYOpen Access

Variations in Kinetic Properties of Ribulose-1,5-bisphosphate Carboxylases among Plants

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Authors

HYHock‐Hin YeohNational University of Singapore MBMurray R. BadgerAustralian National University LWLeslie WatsonNeoGenomics (United States)

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Implication

Comparative enzyme analysis reveals divergent RuBP carboxylase kinetics across diverse plant taxa, indicating an evolutionary link between substrate affinity and CO2-concentrating mechanisms.

Key Points

To determine and compare the kinetic constants Km(CO2) and Km(RuBP) of ribulose-1,5-bisphosphate carboxylase across taxonomically diverse terrestrial and aquatic plant groups.
Measured kinetic constants for ribulose-1,5-bisphosphate carboxylase purified from diverse plant lineages, including C3, C4, and CAM terrestrial plants, aquatic angiosperms, an aquatic bryophyte, and algae.
Evaluated enzyme affinity parameters Km(CO2) and Km(RuBP) in relation to photosynthetic mechanisms and taxonomic classifications among dicotyledons and Poaceae.
Km(CO2) values were 12 to 25 micromolar in C3 and CAM species compared to 28 to 34 micromolar in C4 species, while aquatic plants and algae exhibited values from 30 to 70 micromolar.
Enzyme Km(RuBP) ranged from 10 to 136 micromolar (mean ± sd = 36 ± 20 micromolar) and varied taxonomically rather than by photosynthetic pathway, with crassinucellate dicotyledons measuring 18 ± 4 micromolar versus 25 ± 7 micromolar in tenuinucellate species.
RuBP carboxylase from selected grass lineages (Triticeae, chloridoids, andropogonoids, Microlaena, and Tetrarrhena) yielded lower Km(RuBP) values of 29 ± 11 micromolar compared to 46 ± 10 micromolar in other Poaceae members.

Cite This Study

Yeoh et al. (1981) studied this question.

synapsesocial.com/papers/6ab88cb56d9b6fc8d8a13188 https://doi.org/10.1104/pp.67.6.1151

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Implication

Comparative enzyme analysis reveals divergent RuBP carboxylase kinetics across diverse plant taxa, indicating an evolutionary link between substrate affinity and CO2-concentrating mechanisms.

Variations in Kinetic Properties of Ribulose-1,5-bisphosphate Carboxylases among Plants

Discussion

Member takes

Implication

Key Points

Cite This Study

Variations in Kinetic Properties of Ribulose-1,5-bisphosphate Carboxylases among Plants

Discussion

Member takes

Implication

Key Points

Cite This Study

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