The kinetic data were interpreted in terms of simple first order kinetics for both the anomer exchange and enzymatic reaction. The relevance of such an approach for an enzymatic reaction is questionable, as it is typically described by a Michaelis-Menten reaction kind of scheme, possibly complexified by the presence of a cofactor, as in the present case or of an inhibitor . It is well established that, in general, an order of reaction cannot be defined, and that enzymes obey a well-defined order kinetics to a good approximation only in some particular conditions. Namely, in case of large substrate excess, the kinetics is approximately of zero order, meaning that the kinetic rate is constant with time. In this respect, it is interesting to note that, for comparable substrate polarization in the solid (to within ∼ 20%), the first measured signal intensity after dissolution was roughly an order of magnitude smaller in the presence of the enzyme than in its absence. This is a clear indication that the (fast) reaction has already significantly advanced before the start of acquisition (see Fig. in the Supplementary Information). The assumption of this particular kinetic regime was therefore unlikely.