M. Pirard et al., Effect of mutations found in carbohydrate-deficient glycoprotein syndrome type IA on the activity of phosphomannomutase 2, FEBS LETTER, 452(3), 1999, pp. 319-322
Seven mutant forms of human phosphomannomutase 2 were produced in Esclerich
ia coli and purified. These mutants had a V-max of 0.2-50% of the wild enzy
me and were unstable. The least active protein (R141H) bears a very frequen
t mutation, which has never been found in the homozygous state whereas the
second least active protein (D188G) corresponds to a mutation associated wi
th a particularly severe phenotype, We conclude that total lack of phosphom
annomutase 2 is incompatible with life. Another conclusion is that the elev
ated residual phosphomannomutase activity found in fibroblasts of some pati
ents is contributed by their mutated phosphomannomutase 2, (C) 1999 Federat
ion of European Biochemical Societies.