I have to strongly agree with @nathan_rudman and @rob_marshall that you have to change your design of storing the properties in the list itself and instead add these properties to a system module dimensioned by that List. Like this example.
I do question though why are we allowing users to change properties of a list? generally, these values are constants.
Einas "Give a Man a Fish, and You Feed Him for a Day. Teach a Man To Fish, and You Feed Him for a Lifetime"