Allosteric enzyme An enzyme whose catalytic activity can be modified by the noncovalent binding of a particular metabolite (a modulator)at a site(the ALLOSTERIC SITE)other than the active site.

• 别（变）构酶：这种酶除了有活性中心外，还有一个别构中心，当专一性的代谢物非共价的结合到别构中心上时，它的催化活性即发生改变。