Sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in Xanthomonas campestris
Lipid-linked intermediates are involved in the synthesis of the exopolysaccharide xanthan produced by the bacterium Xanthomonas campestris (L. Ielpi, R. O. Couso, and M. A. Dankert, FEBS Lett. 130:253-256, 1981). In this study, the stepwise assembly of the repeating pentasaccharide unit of xanthan i...
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todo:paper_00219193_v175_n9_p2490_Ielpi2023-10-03T14:22:47Z Sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in Xanthomonas campestris Ielpi, L. Couso, R.O. Dankert, M.A. glucose glucose 1 phosphate glucuronic acid guanosine diphosphate lipid mannose pentasaccharide polyprenoic acid uridine diphosphate glucose uridine diphosphate glucuronic acid xanthan article carbohydrate synthesis gel filtration methylation nonhuman polymerization priority journal Xanthomonas Bacteria (microorganisms) Xanthomonas campestris Lipid-linked intermediates are involved in the synthesis of the exopolysaccharide xanthan produced by the bacterium Xanthomonas campestris (L. Ielpi, R. O. Couso, and M. A. Dankert, FEBS Lett. 130:253-256, 1981). In this study, the stepwise assembly of the repeating pentasaccharide unit of xanthan is described. EDTA-treated X. campestris cells were used as both enzyme preparation and lipid-P acceptor, and UDP-Glc, GDP-Man, and UDP- glucuronic acid were used as sugar donors. A linear pentasaccharide unit is assembled on a polyprenol-P lipid carrier by the sequential addition of glucose-1-P, glucose, mannose, glucuronic acid, and mannose. The in vitro synthesis of pentasaccharide-P-P-polyprenol was also accompanied by the incorporation of radioactivity into a polymeric product, which was characterized as xanthan, on the basis of gel filtration and permethylation studies. Results from two-stage reactions showed that essentially pentasaccharide-P-P-polyprenol is polymerized. In addition, the direction of chain elongation has been studied by in vivo experiments. The polymerization of lipid-linked repeat units occurs by the successive transfer of the growing chain to a new pentasaccharide-P-P-polyprenol. The reaction involves C-1 of glucose at the reducing end of the polyprenol-linked growing chain and C-4 of glucose at the nonreducing position of the newly formed polyprenol-linked pentasaccharide, generating a branched polymer with a trisaccharide side chain. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00219193_v175_n9_p2490_Ielpi |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
glucose glucose 1 phosphate glucuronic acid guanosine diphosphate lipid mannose pentasaccharide polyprenoic acid uridine diphosphate glucose uridine diphosphate glucuronic acid xanthan article carbohydrate synthesis gel filtration methylation nonhuman polymerization priority journal Xanthomonas Bacteria (microorganisms) Xanthomonas campestris |
| spellingShingle |
glucose glucose 1 phosphate glucuronic acid guanosine diphosphate lipid mannose pentasaccharide polyprenoic acid uridine diphosphate glucose uridine diphosphate glucuronic acid xanthan article carbohydrate synthesis gel filtration methylation nonhuman polymerization priority journal Xanthomonas Bacteria (microorganisms) Xanthomonas campestris Ielpi, L. Couso, R.O. Dankert, M.A. Sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in Xanthomonas campestris |
| topic_facet |
glucose glucose 1 phosphate glucuronic acid guanosine diphosphate lipid mannose pentasaccharide polyprenoic acid uridine diphosphate glucose uridine diphosphate glucuronic acid xanthan article carbohydrate synthesis gel filtration methylation nonhuman polymerization priority journal Xanthomonas Bacteria (microorganisms) Xanthomonas campestris |
| description |
Lipid-linked intermediates are involved in the synthesis of the exopolysaccharide xanthan produced by the bacterium Xanthomonas campestris (L. Ielpi, R. O. Couso, and M. A. Dankert, FEBS Lett. 130:253-256, 1981). In this study, the stepwise assembly of the repeating pentasaccharide unit of xanthan is described. EDTA-treated X. campestris cells were used as both enzyme preparation and lipid-P acceptor, and UDP-Glc, GDP-Man, and UDP- glucuronic acid were used as sugar donors. A linear pentasaccharide unit is assembled on a polyprenol-P lipid carrier by the sequential addition of glucose-1-P, glucose, mannose, glucuronic acid, and mannose. The in vitro synthesis of pentasaccharide-P-P-polyprenol was also accompanied by the incorporation of radioactivity into a polymeric product, which was characterized as xanthan, on the basis of gel filtration and permethylation studies. Results from two-stage reactions showed that essentially pentasaccharide-P-P-polyprenol is polymerized. In addition, the direction of chain elongation has been studied by in vivo experiments. The polymerization of lipid-linked repeat units occurs by the successive transfer of the growing chain to a new pentasaccharide-P-P-polyprenol. The reaction involves C-1 of glucose at the reducing end of the polyprenol-linked growing chain and C-4 of glucose at the nonreducing position of the newly formed polyprenol-linked pentasaccharide, generating a branched polymer with a trisaccharide side chain. |
| format |
JOUR |
| author |
Ielpi, L. Couso, R.O. Dankert, M.A. |
| author_facet |
Ielpi, L. Couso, R.O. Dankert, M.A. |
| author_sort |
Ielpi, L. |
| title |
Sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in Xanthomonas campestris |
| title_short |
Sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in Xanthomonas campestris |
| title_full |
Sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in Xanthomonas campestris |
| title_fullStr |
Sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in Xanthomonas campestris |
| title_full_unstemmed |
Sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in Xanthomonas campestris |
| title_sort |
sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in xanthomonas campestris |
| url |
http://hdl.handle.net/20.500.12110/paper_00219193_v175_n9_p2490_Ielpi |
| work_keys_str_mv |
AT ielpil sequentialassemblyandpolymerizationofthepolyprenollinkedpentasacchariderepeatingunitofthexanthanpolysaccharideinxanthomonascampestris AT cousoro sequentialassemblyandpolymerizationofthepolyprenollinkedpentasacchariderepeatingunitofthexanthanpolysaccharideinxanthomonascampestris AT dankertma sequentialassemblyandpolymerizationofthepolyprenollinkedpentasacchariderepeatingunitofthexanthanpolysaccharideinxanthomonascampestris |
| _version_ |
1807323226458554368 |