Sucrose synthetase

More-detailed studies of enzyme specificity towards the structure of the nucleoside residue have been performed with the sucrose synthetase of pea seedlings,339,384,501,502 and with wheat-germ arbutin synthetase.339,364,503 Neither enzyme can use the cytidine,504 isocyti-dine, or N3-methyluridine derivatives as substrates. On the other hand, the a-D-glucopyranosyl pyrophosphate esters of 4-thiouri-... 

Sucrose synthetase from pea seedlings seems to be more specific than similar enzymes from other plants. Unlike them, it cannot accept thymidine 5 -(a-D-glucopyranosyl pyrophosphate) as a substrate.364... 

Stoichiometric quantities of uridine diphosphate glucose were used, in the presence of a transfer enzyme, sucrose synthetase, in the soluble state (extraction given). Coupling with modified D-fructose gave sucroses modified on the D-fructosyl group, on the 1 -3-mmol scale. Thus were prepared l -deoxy-l -fluoro- (59%),98 4 -deoxy-4 -fluoro- (16%), and l -azido-l -deoxy-sucrose (15%).71 6-Deoxy-6-fluoro-D-glucose was isomerized to 6-deoxy-6-fluoro-D-fructose with isomerase, and gave 6 -deoxy-6 -fluoro-sucrose.71... 

Besides the abundant nodulins like Lb, GS, uricase and sucrose synthetase, many other enzymes involved in nodule metabolism are induced during the course of nodule development (see Verma Nadler, 1984). However, owing to the relatively low abundance of these enzymes and their mRNAs in nodules, none of the cognate genes have been cloned and new cloning strategies need to be employed to isolate these relatively less abundantly expressed nodulin sequences. 

Nuclear runoff experiments show that there is transcriptional control of ANP synthesis (at least for Adhl and Adh2, and sucrose synthetase ... 

Pontis, H.G. and Wolosiuk, R.A., Sucrose synthetase. I. Effect of trypsin on the cleavage activity, FEBS Lett., 28, 86-88, 1972. 

Pontis, H.G., Wolosiuk, R.A., Fernandez, L.M., and Bettinelli, B., Role of sucrose and sucrose synthetase in Helianthus tuberosus, in Biochemistry of the Glycosidic Linkage, Academic Press, New York, 1972, pp. 239-265. 

Sakalo, V.D. and Lukashova, R.G., Activity and immunochemical comparison of sucrose synthetase from plant storage organs, Fiziologiya Rastenii, 40, 265-270, 1993. 

Salerno, G.L., Gamundi, S.S., and Pontis, H.G., A procedure for the assay of sucrose synthetase and sucrose phosphate synthetase in plant homogenates, Anal. Biochem., 93, 196-199, 1979. 

Wolosiuk, R.A. and Pontis, H.G., Sucrose synthetase. II. Kinetic mechanism, Arch. Biochem. Biophys., 165, 140-145, 1974. 

Fig. 6.—Hypothetical Model for the Biosynthesis of Cellulose.184 [Numbers refer to reactions catalyzed by the following enzymes 1, invertase (EC 3.2.1.26) 2, sucrose synthetase 3, hexokinase (EC 2.7.1.1) 4, phosphoglucomutase (EC 2.7.5.1) 5, UDP-glucose pyrophosphorylase and 6, 7, and 8, hypothetical reactions in the pathway to cellulose.]...

Sucrose synthetase. The fructose derivatives 1-azido-l-deoxy-, 1-fluoro-l-deoxy-, 6-deoxy-, 6-fluoro-6-deoxy-, and 4-fluoro-4-deoxy-fructose have been used as glycosyl acceptors in the sucrose synthetase-catalyzed synthesis of sucrose analogs12031. 6-Deoxy- and 6-fluoro-6-deoxy-fructose were generated in situ from the corresponding glucose derivatives under catalysis by glucose isomerase[2031. Sucrose synthetase has also been extensively employed in the synthesis of nucleotide sugars[2041. 

Figure 13-9. General scheme for an enzyme-catalyzed synthesis of sucrose with UDP-glucose1821. i) sucrose synthetase ii) pyruvate kinase iii) UDP-glucose pyrophosphorylase iv) inorganic pyrophosphatase.

Grimes, Jones, and Albersheim purified sucrose synthetase from mung beans, and determined that its molecular weight was —10 . 

Results obtained by Leloir and Cardini indicated that two separate enzymes are involved in the biosynthesis, in plants, of sucrose and sucrose phosphate from D-fructose and D-fructose 6-phosphate, respectively in the presence of UDP-D-glucose these enzymes have been partially separated. Slabnik and coworkers succeeded in isolating sucrose synthetase and sucrose 6-phosphate synthetase from potato tubers, and determined some of the properties of the partially purified preparations. The sucrose synthetase showed an optimum activity at 45 and was inhibited completely by ADP and some phenolic D-glucosides, whereas these had no effect on sucrose 6-phosphate synthetase. 

They postulated that UDP-D-glucose may have an important role in the initial step of transformation of sucrose into starch, whereas synthesis of starch is primarily catalyzed by ADP-D-glucose-starch transglycosylase. This concept has been based on the smaller constant of the sucrose synthetase toward UDP as compared with that for ADP, and by the fact that the ADP D-sucrose transglycosylase is specifically inhibited by UDP. From these results, de Fekete and Cardini postulated the following two sequences of reaction for the incorporation of D-glucose into the granule. 

Murata and coworkers, working with a coupling system of sucrose synthetase and starch synthetase, both isolated from ripening rice grains, found that a more efficient transfer of D-glucose- C from sucrose- C to starch occurs in the presence of ADP as compared with UDP, indicating that ADP-D-glucose plays a prominent role in the... 

E3 UDP-sugar phosphorylase. E4 pyrophosphatase. (Below) Synthesis of 6 -deoxy-6 -fluorosucrose. El, sucrose synthetase E2, pyruvate kinase E3, UDP-glucose pyrophosphorylase E4, pyrophosphatase. All enzymes (150 U each) are co-immobilized in polyacrylamide gel. The reactions are carried out in triethanolamine buffer (50 mM) containing MgCl2 (10 mM) with pH being controlled at 7.5 by addition of IN NaOH. The 500-mL reaction mixture contains glucose-... 

Synthesis of Disaccharides and Their Derivatives.- Reference is made to the synthesis of disaccharides from thloglycosldes in Section 2 of this Chapter. In the area of non-reducing di-saccharides, a set of sucrose derivatives have been prepared by enzymic methods as follows 1) l -azldo-l -deoxysucrose from 1-azido-l-deoxy-D-fructose and UDPG with a sucrose synthetase, li)... 

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