| advertisement: compare things at compare-stuff.com! |
In some cases, enzymes will have a binding site for a regulatory protein in the vicinity of the active site. When the regulator binds, it blocks access to the active site for the substrate. This is called competitive inhibition. The same type of inhibition can prevent two binding partners from associating to form an active multimeric protein. Conversely, the association of subunits can enhance function. Protein modifications, such as phosphorylation, can have similar steric effects.