Studies on potato tuber phosphorylase catalyzed reaction in the absence of an exogenous acceptor. II. Characterization of the reaction product

Incubation of potato tuber phophorylase II with [14C]glucose 1-phosphate in the absence of an exogenous acceptor results in the synthesis of a radioactive product, presumably a protein-bound glucan. The carbohydrate moiety of this product was shown to consist of long α-1,4-glucosidic chains. The enz...

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Autores principales: Sivak, M.N., Tandecarz, J.S., Cardini, C.E.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00039861_v212_n2_p537_Sivak
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spelling todo:paper_00039861_v212_n2_p537_Sivak2023-10-03T13:56:56Z Studies on potato tuber phosphorylase catalyzed reaction in the absence of an exogenous acceptor. II. Characterization of the reaction product Sivak, M.N. Tandecarz, J.S. Cardini, C.E. carbon glucan glucose 1 phosphate glucose phosphate glycoprotein isoenzyme phosphorylase affinity chromatography article density gradient centrifugation enzymology isolation and purification metabolism molecular weight plant polyacrylamide gel electrophoresis Carbon Radioisotopes Centrifugation, Density Gradient Chromatography, Affinity Electrophoresis, Polyacrylamide Gel Glucans Glucosephosphates Glycoproteins Isoenzymes Molecular Weight Phosphorylases Plants Support, Non-U.S. Gov't Incubation of potato tuber phophorylase II with [14C]glucose 1-phosphate in the absence of an exogenous acceptor results in the synthesis of a radioactive product, presumably a protein-bound glucan. The carbohydrate moiety of this product was shown to consist of long α-1,4-glucosidic chains. The enzyme itself was originally assumed to be the first glucosyl acceptor in the unprimed reaction. However, as judged by urea-sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the radioactive product is rather resistant to proteolysis and is smaller in size than phosphorylase II. These data are in agreement with those obtained by sucrose density gradient centrifugation and molecular-weight estimation of native products. Thus, some kind of processing postglucosylation has to be proposed to account for the observed decrease in molecular weight. One cannot overlook the probable presence of a low-molecular-weight protein acceptor which copurifies along with phosphorylase II and whose separation from the enzyme can only be achieved upon glucosylation. On the other hand, protein was also found to be present in amylose from potato starch grains. It is therefore suggested that this finding might become an additional evidence of a common biosynthetic pathway for α-1,4-glucans from a precursor protein. © 1981. Fil:Sivak, M.N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Tandecarz, J.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00039861_v212_n2_p537_Sivak
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic carbon
glucan
glucose 1 phosphate
glucose phosphate
glycoprotein
isoenzyme
phosphorylase
affinity chromatography
article
density gradient centrifugation
enzymology
isolation and purification
metabolism
molecular weight
plant
polyacrylamide gel electrophoresis
Carbon Radioisotopes
Centrifugation, Density Gradient
Chromatography, Affinity
Electrophoresis, Polyacrylamide Gel
Glucans
Glucosephosphates
Glycoproteins
Isoenzymes
Molecular Weight
Phosphorylases
Plants
Support, Non-U.S. Gov't
spellingShingle carbon
glucan
glucose 1 phosphate
glucose phosphate
glycoprotein
isoenzyme
phosphorylase
affinity chromatography
article
density gradient centrifugation
enzymology
isolation and purification
metabolism
molecular weight
plant
polyacrylamide gel electrophoresis
Carbon Radioisotopes
Centrifugation, Density Gradient
Chromatography, Affinity
Electrophoresis, Polyacrylamide Gel
Glucans
Glucosephosphates
Glycoproteins
Isoenzymes
Molecular Weight
Phosphorylases
Plants
Support, Non-U.S. Gov't
Sivak, M.N.
Tandecarz, J.S.
Cardini, C.E.
Studies on potato tuber phosphorylase catalyzed reaction in the absence of an exogenous acceptor. II. Characterization of the reaction product
topic_facet carbon
glucan
glucose 1 phosphate
glucose phosphate
glycoprotein
isoenzyme
phosphorylase
affinity chromatography
article
density gradient centrifugation
enzymology
isolation and purification
metabolism
molecular weight
plant
polyacrylamide gel electrophoresis
Carbon Radioisotopes
Centrifugation, Density Gradient
Chromatography, Affinity
Electrophoresis, Polyacrylamide Gel
Glucans
Glucosephosphates
Glycoproteins
Isoenzymes
Molecular Weight
Phosphorylases
Plants
Support, Non-U.S. Gov't
description Incubation of potato tuber phophorylase II with [14C]glucose 1-phosphate in the absence of an exogenous acceptor results in the synthesis of a radioactive product, presumably a protein-bound glucan. The carbohydrate moiety of this product was shown to consist of long α-1,4-glucosidic chains. The enzyme itself was originally assumed to be the first glucosyl acceptor in the unprimed reaction. However, as judged by urea-sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the radioactive product is rather resistant to proteolysis and is smaller in size than phosphorylase II. These data are in agreement with those obtained by sucrose density gradient centrifugation and molecular-weight estimation of native products. Thus, some kind of processing postglucosylation has to be proposed to account for the observed decrease in molecular weight. One cannot overlook the probable presence of a low-molecular-weight protein acceptor which copurifies along with phosphorylase II and whose separation from the enzyme can only be achieved upon glucosylation. On the other hand, protein was also found to be present in amylose from potato starch grains. It is therefore suggested that this finding might become an additional evidence of a common biosynthetic pathway for α-1,4-glucans from a precursor protein. © 1981.
format JOUR
author Sivak, M.N.
Tandecarz, J.S.
Cardini, C.E.
author_facet Sivak, M.N.
Tandecarz, J.S.
Cardini, C.E.
author_sort Sivak, M.N.
title Studies on potato tuber phosphorylase catalyzed reaction in the absence of an exogenous acceptor. II. Characterization of the reaction product
title_short Studies on potato tuber phosphorylase catalyzed reaction in the absence of an exogenous acceptor. II. Characterization of the reaction product
title_full Studies on potato tuber phosphorylase catalyzed reaction in the absence of an exogenous acceptor. II. Characterization of the reaction product
title_fullStr Studies on potato tuber phosphorylase catalyzed reaction in the absence of an exogenous acceptor. II. Characterization of the reaction product
title_full_unstemmed Studies on potato tuber phosphorylase catalyzed reaction in the absence of an exogenous acceptor. II. Characterization of the reaction product
title_sort studies on potato tuber phosphorylase catalyzed reaction in the absence of an exogenous acceptor. ii. characterization of the reaction product
url http://hdl.handle.net/20.500.12110/paper_00039861_v212_n2_p537_Sivak
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