A primer independent form of potato tuber phosphorylase

Tandecarz, Juana S.; Sivak, Mirta N.; Cardini, Carlos E.

doi:10.1016/0006-291x(78)90590-9

Cited by 12 publications

(4 citation statements)

References 16 publications

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“…Similar evidence has been produced by other laboratories concerning glycogen synthesis in Neurospora crassa [9, 101 and bovine retina [ll]. Presumably, the polysaccharides synthesized in vitro correspond to the protein-bound glycogen reported to exist in vivo in rat liver [12] and heart [13], rabbit muscle [14] and bovine retina [ll].Polysaccharides other than glycogen, such as potato starch [15], paramylon (B-1,3-glucan) from EugZenu grucilis [16], P-1,2-glucans from Agrobacterium [17], dextran from Streptococcus mutans and Leuconostoc mesenteroides [18, 191 and glucosaminoglycan from cartilage [20] were also postulated to be synthesized on protein primers. …”

supporting

confidence: 77%

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The initiation of glycogen biosynthesis in rat heart alpha-1,4 glucans tightly associated with glycogen synthase

Blumenfeld

Krisman

1986

Eur J Biochem

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A partially purified glycogen synthase from rat cardiac muscle transferred glucosyl residues from UDP- [14C]glucose to an endogenous protein acceptor in the absence of added primer. After native gel electrophoresis of the enzyme preparation, unprimed activity was detected. Primer-dependent and independent activities were found in the same position. After denaturing gel electrophoresis of the reaction products, radioactivity comigrated with protein. Pulse-chase experiments showed that the size of the reaction products increased as a function of time. These products were degraded by amyloglucosidase, thus suggesting that glycogen-like molecules had grown on the protein acceptor.The activity of the enzyme was markedly reduced upon preincubation with a-amylase. Therefore, preformed protein-bound a-1 ,Cglucans were acting as primers. The glucoprotein acceptor may be a protein strongly associated with glycogen synthease, or alternatively, the enzyme itself.Since the discovery of the enzymes responsible for the formation of a-1 ,Cglucosidic bonds (glycogen synthase) and a-1 ,6-branched linkages (branching enzyme) of glycogen, the biosynthesis of this polysaccharide has presented the unique problem of how primer molecules, which are necessary in order to initiate glycogen synthesis [l], originate.We have previously reported the in vitro synthesis of glycogen apparently attached to protein in crude enzymes systems from rat liver [2-41 and heart [5] and from Escherichiu coli [6, 71, as well as in partially purified preparations from rat heart [8]. Similar evidence has been produced by other laboratories concerning glycogen synthesis in Neurospora crassa [9, 101 and bovine retina [ll]. Presumably, the polysaccharides synthesized in vitro correspond to the protein-bound glycogen reported to exist in vivo in rat liver [12] and heart [13], rabbit muscle [14] and bovine retina [ll].Polysaccharides other than glycogen, such as potato starch [15], paramylon (B-1,3-glucan) from EugZenu grucilis [16], P-1,2-glucans from Agrobacterium [17], dextran from Streptococcus mutans and Leuconostoc mesenteroides [18, 191 and glucosaminoglycan from cartilage [20] were also postulated to be synthesized on protein primers.

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supporting

confidence: 77%

“…Polysaccharides other than glycogen, such as potato starch [15], paramylon (B-1,3-glucan) from EugZenu grucilis [16], P-1,2-glucans from Agrobacterium [17], dextran from Streptococcus mutans and Leuconostoc mesenteroides [18, 191 and glucosaminoglycan from cartilage [20] were also postulated to be synthesized on protein primers.…”

mentioning

confidence: 99%

The initiation of glycogen biosynthesis in rat heart alpha-1,4 glucans tightly associated with glycogen synthase

Blumenfeld

Krisman

1986

Eur J Biochem

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“…A protein primer seems also to be involved in the biosynthesis of glycogen by rat liver (Krisman, 1972;Krisman & Barengo, 197.5) and by Esrherichiu coli (Barengo et a/., 197.5), as well as in the biosynthesis of a pl+3-glucan (paramylon) by Eugleria gracilis (Tomos & Northcote, 1978). By using particulate enzyme preparations from potato, it was found that glucose was transferred from UDP-Glc t o amino acid residues on a n endogenous protein acceptor t o produce a glucoprotein that then accepts further glucose from ADP-Glc, UDP-Glc or glucose I-phosphate (Lavintman er a/., 1974;Tandecarz & Cardini, 1978). A similar mechanism has also been demonstrated with a soluble enzyme preparation from potato.…”

Section: (B) 0-glycosidic Unitsmentioning

confidence: 96%

Comparative Biochemistry of Plant Glycoproteins

Sharon

Lis

1979

Biochemical Society Transactions

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“…Location of primed and unprimed phosphorylase activities on the gels, following electrophoresis, was done as already reported [14].…”

Section: Analytical Non-denaturing Pagementioning

confidence: 99%

α‐Glucan synthesis on a protein primer

Moreno¹,

Cardini²,

Tandecarz³

1987

European Journal of Biochemistry

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Reconstitution experiments with the DEAE-cellulose-treated enzymes, engaged in a two-step mechanism of synthesis of a-glucan bound to protein, are performed. Urea/sodium dodecyl sulfate/polyacrylamide gel electrophoretic analysis of the radioactive products synthesized by the reconstituted system shows highly glucosylated, labeled bands, whose apparent molecular masses change with the acrylamide concentration in the gels. The long carbohydrate chains synthesized during the second step arise from the sequential addition of glucosyl moieties to the glucoprotein formed during the first step. A deglucosylation experiment confirms that the product of the reconstituted system originates from the 38-kDa glucosylated component of the reaction 1 product by the addition of P-amylase-sensitive glucosyl moieties. Our data suggest that specific phosphorylases and starch synthetases are found in potato tuber, which are capable of utilizing reaction 1 product as primer for the synthesis of protein-bound glucan.

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A primer independent form of potato tuber phosphorylase

Cited by 12 publications

References 16 publications

The initiation of glycogen biosynthesis in rat heart alpha-1,4 glucans tightly associated with glycogen synthase

The initiation of glycogen biosynthesis in rat heart alpha-1,4 glucans tightly associated with glycogen synthase

Comparative Biochemistry of Plant Glycoproteins

α‐Glucan synthesis on a protein primer

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