Effect of mutations found in carbohydrate‐deficient glycoprotein syndrome type IA on the activity of phosphomannomutase 2

FEBS Letters

Pirard, Michel²  van Schaftingen, Emile²  Grünewald, Stephanie¹  Matthijs, Gert¹  Schollen, Els¹  Heykants, Leen¹  Jaeken, Jaak³ 

[1] Center of Human Genetics, University of Leuven, Herestraat 49, B-3000 Leuven, Belgium;Laboratory of Physiological Chemistry, ICP and Université Catholique de Louvain, Avenue Hippocrate 75, B-1200 Brussels, Belgium;Department of Pediatrics, University of Leuven, Herestraat 49, B-3000 Leuven, Belgium

关键词: Protein glycosylation;    Phosphomannomutase;    Mannose;    Oligosaccharide;    CDG;    carbohydrate-deficient glycoprotein;    CDG IA;    carbohydrate-deficient glycoprotein syndrome type IA;    PMM;    phosphomannomutase;   

DOI  :  10.1016/S0014-5793(99)00673-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Seven mutant forms of human phosphomannomutase 2 were produced in Escherichia coli and purified. These mutants had a V _max of 0.2–50% of the wild enzyme and were unstable. The least active protein (R141H) bears a very frequent mutation, which has never been found in the homozygous state whereas the second least active protein (D188G) corresponds to a mutation associated with a particularly severe phenotype. We conclude that total lack of phosphomannomutase 2 is incompatible with life. Another conclusion is that the elevated residual phosphomannomutase activity found in fibroblasts of some patients is contributed by their mutated phosphomannomutase 2.

【 授权许可】

Unknown