Biosynthesis of sucrose

Frydman RB, Hassid WZ. Biosynthesis of sucrose with sugar cane leaf preparations. Nature 1963 199 382-383. 

A report has appeared on the enzymatic hydrolysis of a,a-trehalose and various deoxy- and dideoxy-analogues. In a study on the biosynthesis of sucrose, mono-deoxy-glucose analogues of UDP-glucose have been shown to act as donors, but more slowly than UDP-glucose itself. The synthesis of, and conformations adopted... 

Figure 10.9. Reaction pathways for the biosynthesis of sucrose and starch from D-fruc-tose-6-phosphate in plants.

Several types of reaction may be carried out in a chromatographic reactor. The reaction can be chemical or biochemical, taking place on the stationary phase, in the mobile phase, or both. The stationary phase must be chosen to have a good retention (affinity) for at least one component of the reaction system, and in some cases it has to act as a catalyst or catalyst support. Chromatographic reactors are particularly suited to enzyme-catalysed reactions such as the inversion of sucrose and biosynthesis of dextran, to various... 

The sequence of steps in the biosynthesis of the ferritin iron core has been studied by analyzing the incorporation of Fe into ferritin during synthesis of the protein vivo. Ferritin, collected at various intervals after the induction of synthesis, was fractionated according to iron core size by sedimentation through gradients of sucrose (32). Fe appeared first in ferritin with small amounts of Fe, and later, the Fe appeared in fractions further down the gradient as the core size and the ratio... 

A characteristic feature of the SuSy isoforms is a conserved phosphorylated serine residue near the N-terminus [8-10]. In-vivo studies have demonstrated that phosphorylation and dephosphorylation direct the distribution of SuSy isoforms in the plant cell [10-12]. The soluble phosphorylated SuSy interacts with the actin cytoskeleton in the cytoplasm [13], and the dephosphorylated SuSy isoforms are targeted to the cell membrane to form complexes with other enzymes, e.g., glucan synthase, catalyzing cellulose biosynthesis from sucrose [4, 10, 14]. In this respect, recent studies on the dephosphorylated enzymes by cloning and expression of SMS genes in E. coli have shown differences in some biochemical features when compared to the enzymes isolated from the corresponding plant material. Recom-... 

It was shown that, in the maturing seeds, while the synthesis of reserve hemicellulose progresses in the endosperm, a large amount of a trehalose is formed, in addition to sucrose and umbelliferose.92 This trehalose disappears rapidly during the progress of the ripening process, and umbelliferose accumulates continuously. It was predicted that the trehalose may be present in most umbellifers however, the relationship of this disaccharide to the biosynthesis of umbelliferose, and the mechanism involved therein, are not known. 

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