Further studies on the primer formation for glycogen biosynthesis in rat heart.
Using selected incubation conditions we have identified intermediate steps, between the first glucose transferred to protein and the appropriate substrate for glycogen synthase. Mn2+ stimulates the addition of the first, and probably, the second glucose molecule to the acceptor protein but inhibits...
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1993
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01455680_v39_n3_p301_Tolmasky http://hdl.handle.net/20.500.12110/paper_01455680_v39_n3_p301_Tolmasky |
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paper:paper_01455680_v39_n3_p301_Tolmasky2023-06-08T15:12:18Z Further studies on the primer formation for glycogen biosynthesis in rat heart. Tolmasky, Diana Silvia Blumenfeld, Marta Liliana Krisman de Fischman, Clara Rebeca 1,4 glucan 1,4-glucan glucan glucose glucosyltransferase glycogen glycogen synthase glycogenin glycoprotein manganese animal article biosynthesis heart muscle metabolism rat Animals Glucans Glucose Glucosyltransferases Glycogen Glycogen Synthase Glycoproteins Manganese Myocardium Rats Using selected incubation conditions we have identified intermediate steps, between the first glucose transferred to protein and the appropriate substrate for glycogen synthase. Mn2+ stimulates the addition of the first, and probably, the second glucose molecule to the acceptor protein but inhibits further elongation. In the presence of Mn2+ only one radioglucosylated protein band of M(r) 42 kDa was evident. In the absence of Mn2+, two bands of 60.7 and 64.6 kDa were obtained indicating elongation of the glucan chains. After Glc6P addition a family of glucosylated proteins with higher M(r) was obtained, as reported previously. Mn2+ inhibition of the second step, is reversed by PMSF+Glc6P addition. Under these conditions a family of radioglucosylated protein bands with M(r) far in excess of 42 kDa, similar to that obtained without Mn2+, was obtained. Therefore, two different transglucosylating activities were necessary, at least, to prepare the appropriate substrate for glycogen synthase. Based on these observations the model we proposed earlier for glycogen biogenesis is modified. The original "Glycogen Initiator" implies at present two enzymatic activities, Glycogen Initiator 1 (activated by Mn2+) and Glycogen Initiator 2 (inhibited by Mn2+). Fil:Tolmasky, D.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Blumenfeld, M.L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Krisman, C.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1993 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01455680_v39_n3_p301_Tolmasky http://hdl.handle.net/20.500.12110/paper_01455680_v39_n3_p301_Tolmasky |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
1,4 glucan 1,4-glucan glucan glucose glucosyltransferase glycogen glycogen synthase glycogenin glycoprotein manganese animal article biosynthesis heart muscle metabolism rat Animals Glucans Glucose Glucosyltransferases Glycogen Glycogen Synthase Glycoproteins Manganese Myocardium Rats |
| spellingShingle |
1,4 glucan 1,4-glucan glucan glucose glucosyltransferase glycogen glycogen synthase glycogenin glycoprotein manganese animal article biosynthesis heart muscle metabolism rat Animals Glucans Glucose Glucosyltransferases Glycogen Glycogen Synthase Glycoproteins Manganese Myocardium Rats Tolmasky, Diana Silvia Blumenfeld, Marta Liliana Krisman de Fischman, Clara Rebeca Further studies on the primer formation for glycogen biosynthesis in rat heart. |
| topic_facet |
1,4 glucan 1,4-glucan glucan glucose glucosyltransferase glycogen glycogen synthase glycogenin glycoprotein manganese animal article biosynthesis heart muscle metabolism rat Animals Glucans Glucose Glucosyltransferases Glycogen Glycogen Synthase Glycoproteins Manganese Myocardium Rats |
| description |
Using selected incubation conditions we have identified intermediate steps, between the first glucose transferred to protein and the appropriate substrate for glycogen synthase. Mn2+ stimulates the addition of the first, and probably, the second glucose molecule to the acceptor protein but inhibits further elongation. In the presence of Mn2+ only one radioglucosylated protein band of M(r) 42 kDa was evident. In the absence of Mn2+, two bands of 60.7 and 64.6 kDa were obtained indicating elongation of the glucan chains. After Glc6P addition a family of glucosylated proteins with higher M(r) was obtained, as reported previously. Mn2+ inhibition of the second step, is reversed by PMSF+Glc6P addition. Under these conditions a family of radioglucosylated protein bands with M(r) far in excess of 42 kDa, similar to that obtained without Mn2+, was obtained. Therefore, two different transglucosylating activities were necessary, at least, to prepare the appropriate substrate for glycogen synthase. Based on these observations the model we proposed earlier for glycogen biogenesis is modified. The original "Glycogen Initiator" implies at present two enzymatic activities, Glycogen Initiator 1 (activated by Mn2+) and Glycogen Initiator 2 (inhibited by Mn2+). |
| author |
Tolmasky, Diana Silvia Blumenfeld, Marta Liliana Krisman de Fischman, Clara Rebeca |
| author_facet |
Tolmasky, Diana Silvia Blumenfeld, Marta Liliana Krisman de Fischman, Clara Rebeca |
| author_sort |
Tolmasky, Diana Silvia |
| title |
Further studies on the primer formation for glycogen biosynthesis in rat heart. |
| title_short |
Further studies on the primer formation for glycogen biosynthesis in rat heart. |
| title_full |
Further studies on the primer formation for glycogen biosynthesis in rat heart. |
| title_fullStr |
Further studies on the primer formation for glycogen biosynthesis in rat heart. |
| title_full_unstemmed |
Further studies on the primer formation for glycogen biosynthesis in rat heart. |
| title_sort |
further studies on the primer formation for glycogen biosynthesis in rat heart. |
| publishDate |
1993 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01455680_v39_n3_p301_Tolmasky http://hdl.handle.net/20.500.12110/paper_01455680_v39_n3_p301_Tolmasky |
| work_keys_str_mv |
AT tolmaskydianasilvia furtherstudiesontheprimerformationforglycogenbiosynthesisinratheart AT blumenfeldmartaliliana furtherstudiesontheprimerformationforglycogenbiosynthesisinratheart AT krismandefischmanclararebeca furtherstudiesontheprimerformationforglycogenbiosynthesisinratheart |
| _version_ |
1768545920315555840 |