Fig 1. Phosphomannomutase activity of PMM1 and PMM2 on Man-6-P monitored by ³¹P-NMR spectroscopy.

PMM1 or PMM2 (54 μg) were incubated with Man-6-P 1mM and Glc-1,6-P₂ 0.1 mM at 27°C. Panel A) Spectrum of reagents prior to PMM1 addition. Panel B) Spectrum of products after PMM1 addition. Panel C) Spectrum of reagents prior to PMM2 addition. Panel D) Spectrum of products after PMM2 addition. The spectra were accumulated over 40 min. Creatine phosphate (1 mM) was added as an internal standard and all the spectra were referred to it (0 ppm). Resonance assignment was obtained by comparison with pure compounds: 1, Glc-6-P; 2, Man-6-P; 3 and 5, Man-1,6-P₂; 4, Man-1-P; 6 and 7, Glc-1,6-P₂; *, inorganic phosphate.