AI Article Synopsis
- Glycogenin is the initiator of proteoglycogen biosynthesis through a process called intramolecular autoglucosylation, where it adds glucose units to itself.
- The process starts when glycogenin is incubated with UDP-glucose, forming a maltosaccharide that reaches a maximum of 13 glucose units before the reaction stops.
- Even after autoglucosylation halts, glycogenin remains active for further reactions, showing that polysaccharide-bound glycogenin can undergo this process and revealing the limiting factors of glucose polymerization.
Article Abstract
Glycogenin initiates the biosynthesis of proteoglycogen, the mammalian glycogenin-bound glycogen, by intramolecular autoglucosylation. The incubation of glycogenin with UDP-glucose results in formation of a tyrosine-bound maltosaccharide, reaching maximum polymerization degree of 13 glucose units at cessation of the reaction. No exhaustion of the substrate donor occurred at the autoglucosylation end and the full autoglucosylated enzyme continued catalytically active for transglucosylation of the alternative substrate dodecyl-maltose. Even the autoglucosylation cessation once glycogenin acquired a mature maltosaccharide moiety, proteoglycogen and glycogenin species ranging rM 47-200kDa, derived from proteoglycogen, showed to be autoglucosylable. The results describe for the first time the ability of polysaccharide-bound glycogenin for intramolecular autoglucosylation, providing evidence for cessation of the glucose polymerization initiated into the tyrosine residue, by inaccessibility of the acquired maltosaccharide moiety to further autoglucosylation.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.bbrc.2008.07.114 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Evidence for glycogenin autoglucosylation cessation by inaccessibility of the acquired maltosaccharide.
Biochem Biophys Res Commun
October 2008
Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), UNC-CONICET, Departamento de Química Biológica, Facultad de Ciencias Químicas, Haya de la Torre y Medina Allende, Ciudad Universitaria, X5000HUA Córdoba, Argentina.
Article Synopsis
- Glycogenin is the initiator of proteoglycogen biosynthesis through a process called intramolecular autoglucosylation, where it adds glucose units to itself.
- The process starts when glycogenin is incubated with UDP-glucose, forming a maltosaccharide that reaches a maximum of 13 glucose units before the reaction stops.
- Even after autoglucosylation halts, glycogenin remains active for further reactions, showing that polysaccharide-bound glycogenin can undergo this process and revealing the limiting factors of glucose polymerization.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!