The Active Species of “CO2” Utilized by Ribulose Diphosphate Carboxylase

Cooper, Terrance G.; Filmer, David L.; Wishnick, Marcia; Lane, M. Daniel

doi:10.1016/s0021-9258(18)91899-5

Cited by 212 publications

(20 citation statements)

References 8 publications

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“…Even with the liquid phase concentration of C02 in diffusion equilibrium with atmospheric C02, the turnover for the reaction catalysed by ribulose diphosphate carboxylase would be quite inadequate to account for its operation as an integral reaction of photosynthesis (Hatch & Slack, 1970b). The equilibrium concentration of C02 in solution would be about 7/,M but the Km of ribulose diphosphate carboxylase for C02 is at least 50 times this concentration (Cooper, Filmer, Wishnick & Lane, 1969;). In contrast, even with C02 concentrations well below 7,um the activity and Km of phosphoenolpyruvate carboxylase for C02 in C4-pathway species would permit a turnover sufficient to account for its operation in the primary C02-fixing process .…”

Section: Discussionmentioning

confidence: 99%

The C4-pathway of photosynthesis. Evidence for an intermediate pool of carbon dioxide and the identity of the donor C4-dicarboxylic acid

Hatch

1971

Biochemical Journal

174

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1. Leaves were exposed to (14)CO(2) under steady-state conditions for photosynthesis. The kinetics of entry or loss of label in pools of CO(2) and other compounds was examined during the period of the pulse and a ;chase' with (12)CO(2). 2. With maize the kinetics of labelling of the major CO(2) pool and of depletion of label during a ;chase' was consistent with this pool being derived from the C-4 of malate and being the precursor of the C-1 of 3-phosphoglycerate. 3. Similar results were obtained for Amaranthus leaves except that the C-4 of aspartate rather than malate was apparently the primary source of CO(2). 4. The size and turnover time of the CO(2) and C(4) acid pools was calculated. These results provided the basis for estimating the concentration of CO(2) in the bundle-sheath cells or chloroplasts assuming the pool was largely restricted to one or other of these compartments. 5. These findings are considered in relation to current schemes for the C(4)-pathway and the operation of a CO(2) concentrating mechanism to serve ribulose diphosphate carboxylase.

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Section: Discussionmentioning

confidence: 99%

The C4-pathway of photosynthesis. Evidence for an intermediate pool of carbon dioxide and the identity of the donor C4-dicarboxylic acid

Hatch

1971

Biochemical Journal

174

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“…In photosynthetic organisms, ribulose-1,5-bisphosphate carboxylase-oxygenase (RuBisCO) catalyzes a reaction essential to C i fixation and requires CO 2 as the obligatory substrate (Cooper et al 1969). Symbiodinium harbors a unique form II RuBisCO (Rowan et al 1996) which has very low affinity to CO 2 but binds strongly to O 2 (Morse et al 1995).…”

Section: Ca2-like Is Localized To the Cytoplasm Of Cells Around The Zooxanthellal Tubules In The Outer And Inner Mantlementioning

confidence: 99%

Carbonic anhydrase 2‐like in the giant clam, Tridacna squamosa : characterization, localization, response to light, and possible role in the transport of inorganic carbon from the host to its symbionts

Koh

Hiong

et al. 2017

Physiol Rep

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The fluted giant clam, Tridacna squamosa, lives in symbiosis with zooxanthellae which reside extracellularly inside a tubular system. Zooxanthellae fix inorganic carbon (Ci) during insolation and donate photosynthate to the host. Carbonic anhydrases catalyze the interconversion of CO 2 and HCO3−, of which carbonic anhydrase 2 (CA2) is the most ubiquitous and involved in many biological processes. This study aimed to clone a CA2 homolog (CA2‐like) from the fleshy and colorful outer mantle as well as the thin and whitish inner mantle of T. squamosa, to determine its cellular and subcellular localization, and to examine the effects of light exposure on its gene and protein expression levels. The cDNA coding sequence of CA2‐like from T. squamosa comprised 789 bp, encoding 263 amino acids with an estimated molecular mass of 29.6 kDa. A phenogramic analysis of the deduced CA2‐like sequence denoted an animal origin. CA2‐like was not detectable in the shell‐facing epithelium of the inner mantle adjacent to the extrapallial fluid. Hence, CA2‐like is unlikely to participate directly in light‐enhanced calcification. By contrast, the outer mantle, which contains the highest density of tertiary tubules and zooxanthellae, displayed high level of CA2‐like expression, and CA2‐like was localized to the tubule epithelial cells. More importantly, exposure to light induced significant increases in the protein abundance of CA2‐like in the outer mantle. Hence, CA2‐like could probably take part in the increased supply of inorganic carbon (Ci) from the host clam to the symbiotic zooxanthellae when the latter conduct photosynthesis to fix Ci during light exposure.

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“…(b) Carbon Carboxylation of ribulose-1,5-biphosphate (RuBp) by rubisco in the early Earth was probably unlimited by the availability of CO 2 , leading to the evolution of a rubisco with particularly low substrate affinity (K m Z 20-100 mM; Cooper et al 1969;Badger et al 1998). rubisco, however, can also catalyse the oxidation of RuBp and this reaction, termed 'photorespiration', became significant following the development of oxygenic photosynthesis.…”

Section: Nutrientsmentioning

confidence: 99%

Evolved physiological responses of phytoplankton to their integrated growth environment

Behrenfeld

Halsey

Milligan

2008

Phil. Trans. R. Soc. B

184

159

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Phytoplankton growth and productivity relies on light, multiple nutrients and temperature. These combined factors constitute the 'integrated growth environment'. Since their emergence in the Archaean ocean, phytoplankton have experienced dramatic shifts in their integrated growth environment and, in response, evolved diverse mechanisms to maximize growth by optimizing the allocation of photosynthetic resources (ATP and NADPH) among all cellular processes. Consequently, co-limitation has become an omnipresent condition in the global ocean. Here we focus on evolved phytoplankton populations of the contemporary ocean and the varied energetic pathways they employ to solve the optimization problem of resource supply and demand. Central to this discussion is the allocation of reductant formed through photosynthesis, which we propose has the following three primary fates: carbon fixation, direct use and ATP generation. Investment of reductant among these three sinks is tied to cell cycle events, differentially influenced by specific forms of nutrient stress, and a strong determinant of relationships between light-harvesting (pigment), photosynthetic electron transport and carbon fixation. Global implications of optimization are illustrated by deconvolving trends in the 10-year global satellite chlorophyll record into contributions from biomass and physiology, thereby providing a unique perspective on the dynamic nature of surface phytoplankton populations and their link to climate.

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The Active Species of “CO2” Utilized by Ribulose Diphosphate Carboxylase

Cited by 212 publications

References 8 publications

The C4-pathway of photosynthesis. Evidence for an intermediate pool of carbon dioxide and the identity of the donor C4-dicarboxylic acid

The C4-pathway of photosynthesis. Evidence for an intermediate pool of carbon dioxide and the identity of the donor C4-dicarboxylic acid

Carbonic anhydrase 2‐like in the giant clam, Tridacna squamosa : characterization, localization, response to light, and possible role in the transport of inorganic carbon from the host to its symbionts

Evolved physiological responses of phytoplankton to their integrated growth environment

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