Simple determination of the CO sub 2 /O sub 2 specificity of Ribulose-1,5-bisphosphate carboxylase/oxygenase by the specific radioactivity of ( sup 14 C) glycerate 3-phosphate

Journal Article · Sat Feb 01 00:00:00 EST 1992 · Plant Physiology; (United States)

OSTI ID:7236274

Zhu, Genhai; Jensen, R G; Hallick, R B; Wildner, G F ^[1]

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1. Univ. of Arizona, Tucson (United States)

A new method is presented for measurement of the CO{sub 2}/O{sub 2} specificity factor of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). The ({sup 14}C)3-phosphoglycerate (PGA) from the Rubisco carboxylase reaction and its dilution by the Rubisco oxygenase reaction was monitored by directly measuring the specific radioactivity of PGA. {sup 14}CO{sub 2} fixation with Rubisco occurred under two reaction conditions: carboxylase with oxygenase with 40 micromolar CO{sub 2} in O{sub 2}-saturated water and carboxylase only with 160 micromolar CO{sub 2} under N{sub 2}. Detection of the specific radioactivity used the amount of PGA as obtained from the peak area, which was determined by pulsed amperometry following separation by high-performance anion exchange chromatography and the radioactive counts of the ({sup 14}C)PGA in the same peak. The specificity factor of Rubisco from spinach (Spinacia oleracea L.) (93 {plus minus} 4), from the green alga Chlamydomonas reinhardtii (66 {plus minus} 1), and from the photosynthetic bacterium Rhodospirillum rubrum (13) were comparable with the published values measured by different methods.

• OSTI ID: 7236274
• Journal Information: Plant Physiology; (United States), Vol. 98:2; ISSN 0032-0889
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
RIBULOSE DIPHOSPHATE CARBOXYLASE
SPECIFICITY
BIOLOGICAL PATHWAYS
CARBON 14 COMPOUNDS
CARBON DIOXIDE
CARBOXYLATION
CHLAMYDOMONAS
OXYGEN
PHOTOSYNTHETIC BACTERIA
RADIOACTIVITY
SPINACH
TRACER TECHNIQUES
ALGAE
CARBON COMPOUNDS
CARBON OXIDES
CARBON-CARBON LYASES
CARBOXY-LYASES
CHALCOGENIDES
CHEMICAL REACTIONS
CHLOROPHYCOTA
ELEMENTS
ENZYMES
FOOD
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LYASES
MAGNOLIOPHYTA
MAGNOLIOPSIDA
MICROORGANISMS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLANTS
PROTEINS
UNICELLULAR ALGAE
VEGETABLES
550201* - Biochemistry- Tracer Techniques