Ribulose-1,5-biphosphate carboxylase

Van den Broek, G., Timko, M.P., Kausch, A.P., Cashmore, A.R., Van Montagu, M. Herrera-Estrella, L. (1985). Targeting of a foreign protein to chloroplasts by fusion to the transit peptide from the small subunit of ribulose 1,5-biphosphate carboxylase. Nature, 313, 358-63. 

A ribulose-1,5 -biphosphate carboxylase/oxygenase Mg2+ formation of an enediol(ate) addition of either C02 or 02/C-C bond cleavage... 

The general validity of these relationships has also been demonstrated with -lactoglobulin (21), ribulose 1,5-biphosphate carboxylase ( ), and soy glycinin (27). 

In the case of the major cytoplasmic protein of leaves, ribulose 1,5-biphosphate carboxylase (RUBISCO), the surface rheological properties and foam stability were maximum at pH 5.5, close to the isoelectric point (pH 4.8) and all parameters measured were greater than any other protein studied (2 ). This may be related to the large molecular size of RUBISCO, i.e. 560 000 daltons, and its disulfide stabilized globular structure. 

Martin, J. S. and M. M. Martin, Taimin assays in ecological studies. Precipitation of ribulose-1,5-biphosphate carboxylase/ oxygenase by tannic acid, quebracho, and oak foliage extracts, J. Chem. Ecol., 9, 285-294 (1983). 

H2CO is an abbreviation for a carbohydrate. The reaction is a part of the Calvin cycle. The enzyme necessary to carry out the binding of CO2 is called ribulose-1,5-biphosphate carboxylase oxygenase (RuBisCO). The mechanisms are not fully known. The cofactor ribulose-1,5-biphosphate, a rather small sugar phosphate molecule, binds to CO2 after abstraction of a proton. A covalent bond is formed between RuBis and CO2 (Figure 15.12). 

A-Substituted carbamic acids or their anions play a key role as intermediates in several biological processes (carboxylations by biotin enzymes photosynthetic activation of CO2 promoted by Rubisco (ribulose 1,5-biphosphate carboxylase) glucuronidation, etc.) [10, 11, 31, 32]. 

Atmospheric CO2 first moves through the stomata, dissolves into leaf water and enters the outer layer of photosynthetic cells, the mesophyll cell. Mesophyll CO2 is directly converted by the enzyme ribulose biphosphate carboxylase/oxygenase ( Rubisco ) to a six carbon molecule that is then cleaved into two molecules of phosphoglycerate (PGA), each with three carbon atoms (plants using this photosynthetic pathway are therefore called C3 plants). Most PGA is recycled to make ribulose biphosphate, but some is used to make carbohydrates. Free exchange between external and mesophyll CO2 makes the carbon fixation process less efficient, which causes the observed large C-depletions of C3 plants. 

Jordan DB, Ogren WL Species variation in the specificity of ribulose biphosphate carboxylase/oxygenase, Afafure 291 513—515, 1981. 

CO2 are fixed into sugar (glucose) and mediated by the enzyme rubisco (ribulose-l-5-biphosphate carboxylase). It occurs in the stroma of chloroplasts. The Calvin cycle is also known as the dark reaction, as opposed to the first-stage light reactions. 

BRs increase C02 fixation (an indication of cytoplasmic malate synthesis via phosphoenol pyruvate carboxylase, PEP carboxylase this activity results in the accumulation of fraction-1 protein) and also in vivo C02 fixation by ribulose biphosphate action... 

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