Some articles on hmao:

Monoamine Oxidase B - Structure
... hMAO-A has a single cavity that exhibits a rounder shape and is larger in volume than the "substrate cavity" of hMAO-B ... The first cavity of hMAO-B has been termed the entrance cavity (290 Å3), the second substrate cavity or active site cavity (~390 Å3) – between both an isoleucine199 side-chain serves as a gate ... shown to be important in defining the inhibitor specificity of hMAO B ...