Properties of carbohydrate‐free recombinant glycogenin expressed in an Escherichia coli mutant lacking UDP‐glucose pyrophosphorylase activity

FEBS Letters

Lomako, Wieslawa M.¹  Alonso, Miriam D.¹  Lomako, Joseph¹  Preiss, Jack²  Whelan, William J.¹ 

[1] Department of Biochemistry and Molecular Biology, University of Miami School of Medicine (M823), PO Box 016129, Miami, FL 33101, USA;Department of Biochemistry, Michigan State University, East Lansing, MI 48824, USA

关键词: Glycogenin;    Apo-glycogenin;    Carbohydrate-free glycogenin;   

DOI  :  10.1016/0014-5793(94)00962-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Glycogenin, the self-glucosylating primer for glycogen synthesis is expressed in wild-type E. coli as a recombinant protein in an already partly glucosylated form owing to the presence of its substrate UDP-glucose. By using an E. coli mutant strain lacking in UDP-glucose pyrophosphorylase activity, we have succeeded in expressing carbohydrate-free glycogenin (apo-glycogenin) in good yield. When provided with UDPxy-lose, it autocatalytically adds 1 xylose residue. With UDP-glucose, an average of 8 glucose residues are added. However release of the self-synthesized maltosaccharide chains with isoamylase reveals them to be a mixture. Chains as long as 11 glucose residues (maltoundecaose) are present. The ability of recombinant apo-glycogenin to self-glucosylate is further proof that a separate enzyme is not needed for the addition of the first glucose residue to Tyr-194 of the protein.

【 授权许可】

Unknown