ping-pong mechanism(redirected from double displacement mechanism)
a special multisubstrate reaction in which, for a two-substrate, two-product (that is, bi-bi) system, an enzyme reacts with one substrate to form a product and a modified enzyme, the latter then reacting with a second substrate to form a second, final product, and regenerating the original enzyme. An example of such a mechanism is found in the aminotransferases. More complex ping-pong mechanisms exist for enzymes having more than two substrates.
Synonym(s): double displacement mechanism