Sucrose enzymic synthesis

Indirect evidence of the reversal of enzymic synthesis of levan has recently been obtained.10Ba Enzyme preparations from B. subtilis were shown to contain an enzyme capable of hydrolyzing levan (in addition to the levan-synthesizing enzyme) in a system composed of D-glucose, levan, yeast invertase (to hydrolyze sucrose formed) and the B. subtilis enzyme preparation. 

The first group is comprised that of compounds which potentially could be degraded to form G-l-P by phosphorolysis by beta-linkage specific enzymes. They include IPTGlu, cellobiose, sophorose, salicin, and sucrose. Addition of these compounds, or exogenous G-l-P, to Solka Floe fermentations improved maximum cellulase yields from 171 to 309%, and the time period for enzyme synthesis was reduced from 95 to 59% compared with using Solka Floe only. 

D. R. Patil, D. G. Rethwisch, and J. S. Dordick, Enzymic synthesis of a sucrose-containing linear polyester in nearly anhydrous organic media, Biotechnol. Bioeng., 37 (1991) 639-646. 

One of the main characteristics of this enzyme system is the unique role played by sucrose as the donor of D-glucosyl groups. Even the closely allied isomer, a-D-galactopyranosyl /3-n-fructofuranoside is inactive in this enzymic reaction. The results of work on the enzymic synthesis of starch from D-glucosyl phosphate raised a question as to whether a phosphoryla-... 

DAHP synthetase, 251, 255 Dehydroquinase, 258 Dehydroshikimate riductase, 259 Dextrans, 341 acid hydrolysis of, 349 chain lengths of, 345, 346 cuprammonium complexes of, 355 electron microscope studies on, 349 enzymic synthesis of, 342, 345, 355 from sucrose, 342 flow birefringence studies on, 349 fructose-containing, 359 infrared absorption spectra of, 352 isolation of, 343... 

The enzymic synthesis of sucrose resulted in some publicity that came to the attention of officials of the Coca Cola Company, who were having difficulty in obtaining sucrose because of wartime rationing. The company sent a representative to Berkeley to ascertain whether commercial quantities of sucrose could be made by the enzymic method. Hassid and his associates were away on vacation at the time, so the Coca Cola emissary discussed the problem with Prof. 

Sucrose. See also, Sugar, enzymic synthesis of, 6, 29-48 structure and configuration of, 4, 1-35 utilization of, 4, 293-336... 

Another mechanism for the enzymic synthesis of saccharides is one that occurs through transfer of the glycosyl group from a glycosyl phosphate to an appropriate acceptor. An example of such a reaction is the synthesis of sucrose by the enzyme, sucrose phosphorylase, found in Pseudomonas saccharophila ... 

The synthesis of sucrose by Leloir and collaborators has been discussed previously. These workers found that UDP-D-glucose is the D-glucose donor for formation of sucrose. The synthesis takes place by means of two separate enzymes, one utilizing D-fructose as the acceptor, and the other, D-fructose 6-phosphate. The sucrose phosphate formed in the second reaction is hydrolyzed by a phosphatase, resulting in the formation of free sucrose. As the equilibrium of the reaction for the formation of sucrose phosphate lies to the right, and inasmuch as the large accumulation of sucrose in some plants could be better accounted for by hydrolysis of the sucrose phosphate with phosphatase (which is a practically irreversible reaction), it was suggested that sucrose in plants is most likely synthesized by way of the sucrose phosphate intermediate. 

A fructan. See Fructans, F-43. Prod, comly. by enzymic synthesis from sucrose. Isol. from horse chestnut (Aes-culus hippocastanum), Lycoris radiata, tulips and Leucojum spp., seeds of onions and roots of Asparagus. Low-calorie sweetening agent for food and chewing gum. Constit. of neosugar which improves the intestinal flora in humans. Cryst. (MeOH/EtOH) cryst. 

Sucrose + inorganic phosphate = a-n-glucose 1-phosphate -f- n-fructose Using a-D-glucose 1-phosphate and D-fructose, they prepared sucrose, which was isolated in crystalline form. (See Enzymic synthesis of oligosaccharides, p. 520). 

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