[asgodoy]

Hi all

I'm working with this enzyme that can be used to different substrates, all long chain carbohydrates. I'm trying to set Km and other kinetic constants for two of those substrates, that are CMC and xyloglucan. The problem where is that both of them don't have a well defined molecular mass, basically because the chain size varies a lot... for that reason, instead of defining Km in mM, I'm using g/L has concentration unit. This should not be a problem for individual kinetics, but it will be to compare substrates parameters (for example, Kcat/Km).Anyone have a tip of what can I do about?

Thank you all

[Yggdrasil]

It's hard to provide guidance without knowing more details about the enzyme.  For example, if the enzyme could act only on the reducing ends of sugars, you could define the substrate concentration by measuring the concentration of reducing ends in your substrate sample.