Hill coefficient and coperativity, Hill equation

Hill equation
fraction of occupied sites = 1 /((K/L)^n+1)  for positive n

When n -> -n,

the Hill equation become:
fraction of occupied sites = 1/ ((L/K)^n + 1)
which can be used to model inhibition.

http://en.wikipedia.org/wiki/Hill_equation_%28biochemistry%29