Sucrose phosphorylases

Maltose phosphorylase cannot carry out a similar reaction. The P exchange reaction of sucrose phosphorylase is accounted for by a double-displacement mechanism where E = E-glucose ... 

Thus, in the presence of just Pi and glucose-l-phosphate, sucrose phosphorylase still catalyzes the second reaction and radioactive Pi is incorporated into glucose-l-phosphate over time. 

TRETHEWEY, R.N., FERNIE, A.R., BACHMANN, A., FLEISCHER-NOTTER, H., GEIGENBERGER, P, WILLMITZER, L., Expression of a bacterial sucrose phosphorylase in potato tubers results in a glucose-independent induction of glycolysis, Plant Cell Environ., 2001, 24, 357-365. 

The dried bacteria also contain invertase and this hydrolytic enzyme competes with the sucrose phosphorylase for sucrose. However, it is possible to eliminate most of the invertase from the bacterial preparations by several precipitations with ammonium sulfate. Using a partially purified sucrose phosphorylase preparation and a mixture of... 

That the same enzyme,28 sucrose phosphorylase, is involved in the reaction of L-arabinose is indicated by the following observation. When L-arabinose is added to a mixture containing the enzyme, D-glucose-1-phosphate and D-fructose, of which the last is present in insufficient concentration to give the maximum rate of sucrose formation, an increase... 

Sucrose phosphorylase can then be regarded as a rather versatile transglucosidase, capable of exchanging glycosidic and ester bonds and of donating D-glucose to a variety of substrates such as ketoses, an aldose, inorganic phosphate and arsenate. 

Whereas /3-fructofuranosidase catalyzes the irreversible64 hydrolytic separation of /3-n-fructofuranosyl from its glucosidic partner in sucrose, transglucosidase (sucrose phosphorylase) accelerates the reversible transfer of the glucose residue of sucrose from fructofuranosyl to another acceptor (c/. equations 3 and 4) ... 

The enzyme has been found in Leuconostoc mesenteroides66 and Pseudomonas saccharophila.6 In a series of outstanding researches Doudoroff and Hassid with associates investigated the specificity requirements of sucrose phosphorylase from P. saccharophila. It was found that the enzyme exhibits an absolute specificity for the D-glucose moiety of its... 

An enzymatic reaction intermediate formed by acylation of an acetal hydroxyl group. Such an intermediate is thought to occur in a number of reactions involving carbohydrates. The sucrose phosphorylase reaction is thought to proceed by way of an acyl-glucosyl intermediate. 

An example of an enzyme that exhibits arsenolysisis is sucrose phosphorylase an enzyme that catalyzes the reaction ... 

SELENOPHOSPHATE SYNTHETASE STARCH PHOSPHORYLASE SUCCINYL-CoA SYNTHETASE SUCROSE PHOSPHORYLASE TUBULIN.TYROSINE LIGASE ORTHOPHOSPHATE CONTINUOUS ASSAY Orthovanadate,... 

Recently Kuriki and coworkers succeeded in producing glucose-1-phosphate in situ during the enzymatic polymerization of amylose. By using sucrose phosphorylase or cellobiose phosphorylase, the monomer was produced during the polymerization from inorganic phosphate and sucrose or cellobiose, respectively [119-121]. 

Arsenate similarly replaces phosphate in various phosphorolysis reactions, so that sucrose phosphorylase catalyzes the hydrolysis of sucrose in its presence (23), potato phosphorylase can hydrolyze amylose and amylopectin (24), nucleoside phosphorylase can hydrolyze inosine... 

Double-displacement mechanisms. In a doubledisplacement mechanism sucrose phosphorylase would catalyze two consecutive single displacements, each with inversion. A nucleophilic group of the enzyme would react in Eq. 12-7, step a. In step b, a phosphate would react to regenerate the enzyme with its free nucleophilic group -B. ... 

Kinetics. In a double-displacement mechanism the enzyme shuttles between free enzyme and the intermediate carrying the substrate fragment (here, the glycosyl enzyme). With sucrose phosphorylase the maximum velocity varies with the concentrations of sucrose and HP042 in the characteristic fashion expected for this "ping-pong" mechanism (Eq. 9-47)43... 

Arsenate will replace phosphate in all phospho-rolytic reactions, e.g., in the cleavage of glycogen by glycogen phosphorylase, of sucrose by sucrose phosphorylase, and in the action of purine nucleoside phosphorylase.b Glucose 1-arsenate or ribose-1-arsenate is presumably a transient intermediate which is hydrolyzed to glucose. The overall process is called arsenolysis. Another reaction in which arsenate can replace phosphate is the oxidation of glyceraldehyde 3-phosphate in the presence of P to form 1,3-bisphosphoglycerate ... 

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