Studies on the Schardinger Dextrins. III. Redistribution Reactions of Macerans Amylase<sup>1</sup>

Norberg, Ethelda; French, Dexter

doi:10.1021/ja01159a036

Cited by 64 publications

(19 citation statements)

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“…Enzymes catalyzing analogous transfer reactions have been reported in extracts of Bacillius inacerans (25), blood plasma (22), germinated green gram (24), and minced algae (6). Similarily, a recently reported cabbage leaf enzyme (17) produced several oligosaccharides from concentrated maltose solutions.…”

supporting

confidence: 54%

Properties of Glucosyltransferase and Glucan Transferase from Spinach

Linden

Tanner²,

Kandler³

1974

Plant Physiol.

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A glucosyl and a glucosyl-glucan transferase activity from spinach (Spinacia oleracea L. var. Matador) leaves have been partially purified and characterized. The latter activity (fraction 1 after diethylaminoethylcellulose chromatography) is responsible for the transfer of glucosyl as well as of maltosyl, maltotriosyl, and higher homologous residues to glucose giving rise to maltose and the correspondingly larger molecules. This fraction also shows p-amylase activity. The transfer takes place only to glucose; maltose, as well as other ac-1,4-glucans, serve as donors. The enzyme fraction 2 is amylase-free and catalyzes only the transfer of glucosyl moieties, again with high acceptor specificity to glucose. Maltose and larger o-1,4-glucans, with the exception of maltotriose and maltotetraose, act as donors. The physiological function of these enzymes mav be the formation of oligosaccharide primers for starch synthetase or phosphorylase.Maltose was first recognized to participate in 1,4-to 1,4-glycosyl transfer reactions with extracellular enzymes of Escherichzia coli (1, 7), which synthesized members of the maltodextrin series from maltose. Enzymes catalyzing analogous transfer reactions have been reported in extracts of Bacillius inacerans (25), blood plasma (22), germinated green gram (24), and minced algae (6). Similarily, a recently reported cabbage leaf enzyme (17) produced several oligosaccharides from concentrated maltose solutions.In 1961 Edelman and Keys (8), described an enzyme from wheat germ which catalyzed the transfer of the nonreducing end glycosyl moiety of maltose to "C-glucose with reformation of "C-maltose, as in reaction 1.O-0 + 0* = 0-0*+In reactions 1 through 5, 0 represents a glucosyl unit, 0 represents a reducing glucosyl unit, 0* represents a "C-labeled glucosyl unit,-represents an a-1, 4-linkage, and represents continuation of such bonding as in amylose.The enzymatic activities described in this paper catalyzed reaction 1 as well as some reactions similar to, but not identical with, those of D-enzyme (EC 2.4.1 f; 1,4-glucan:a-1,4-glucan 4-glucosyltransferase) from potato (15,26,27,30,31). Other properties of the enzymatic reactions upon preliminary purification are described.MATERIALS AND METHODS Sources of Chemicals. Litner soluble starch and shellfish glycogen were purchased from Schuhardt, Munich. Amylopectin was prepared from fresh potato juice from which the amylose was precipitated with 1-butanol. Pure maltose was a generous gift from the laboratory of J. F. Robyt. Other maltodextrins were prepared from a fungal amylase digest of amylose precipitated three times (Sigma, St. Louis), separated on a charcoal-celite column (10), and purified by paper chromatography on formic acid and water-washed Whatman No. 1 paper. Other oligosaccharides were from commercial sources and were purified in the same way. Other materials were reagent grade.Radioactive compounds were obtained from the Radiochemical Centre. Amersham, with the exception of the following: 2-deoxy-glycose and a-D-glucos...

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supporting

confidence: 54%

Properties of Glucosyltransferase and Glucan Transferase from Spinach

Linden

Tanner²,

Kandler³

1974

Plant Physiol.

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“…with 4-a-glucanotransferases from bacteria (7,23) and plants (8,17,18,26). Glucose has been found to be the best acceptor for potato D-enzyme.…”

Section: Km For Maltotriosementioning

confidence: 98%

“…Dextrins that have been demonstrated to be substrates for 4-a-glucanotransferases include maltose (1,2,7,18,20), maltotriose (11,26), larger maltodextrins (1 1, 25), and Schardinger (cyclic) dextrins (23). Chloroplast D-enzyme cannot utilize maltose as substrate (Table II, Fig.…”

Section: Km For Maltotriosementioning

confidence: 99%

Characterization of Pea Chloroplast D-Enzyme (4-α-d-Glucanotransferase)

Kakefuda

Duke²

1989

Plant Physiol.

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Pea (Pisum sativum L.) chloroplast D-enzyme (4-a-D-glucanotransferase, EC 2.4.1.25) was purified greater than 750-fold and partially characterized. It is a dimer with a subunit M, of ca. 50,000. Optimal activity is between pH 7.5 and 8.0 with maltotriose as substrate and the enzyme's Km for maltotriose is 3.3 millimolar. Chloroplast D-enzyme converts maltotriose to maltopentaose and glucose via the exchange of a-1,4-glycosidic linkages. Maltotriose acts either as a donor or acceptor of a maltosyl group. The enzyme has highest activity with maltotriose as substrate. As initial substrate degree of polymerization is increased to maltoheptaose, D-enzyme activity drops to zero at 10 millimolar substrate concentrations and by 70% at 1 millimolar concentrations. The enzyme cannot use maltose as a substrate. Glucose was found to be a suitable acceptor substrate for this D-enzyme. Addition of glucose to incubation mixtures, or production of glucose by D-enzyme, prevents the synthesis of maltodextrins larger than maltopentaose. Removal of glucose produced by Denzyme activity with maltotriose as substrate resulted in the synthesis of maltopentaose and maltodextrins with sufficient degrees of polymerization to be suitable substrates for pea chloroplast starch phosphorylase. The possible role of D-enzyme in pea chloroplast starch metabolism is discussed.Pea chloroplasts contain 4-a-glucanotransferase (transglycosylase) activity equal to that of the total hydrolytic starch degrading activity, and eightfold greater than starch phosphorylase activity ( 12). 4-a-Glucanotransferase alters the degrees of polymerization in a population of maltodextrins by the simultaneous hydrolysis and condensation of a-1,4-linkages between maltodextrins. For example, potato 4-a-glucanotransferase can utilize two maltotrioses (G33) to produce glucose (GI) and maltopentaose (G5) or it can utilize G5 and GI to produce two G3s (1 1

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“…The dextrins were used previously in the purification of salivary amylase [13], but were less effective than maltose for the plasma enzyme. At 10 g./liter (0.28 molar), maltose routinely resulted in elution of 90-95 % of the adsorbed enzyme.…”

Section: System Of Fractionationmentioning

confidence: 99%