PLP is seen bound covalently to the active sites of aminotransferases via structure determination The reaction occurs via a typical ping-pong mechanism: the first product leaves before the second substrate enters An interconversion between an aldimine(醛亚胺 and a ketimine(酮亚胺) is proposed to occur via a quinonoid(醌烈的) intermediate during the transamination reaction. PLP act in a variety of other reactions at the a, B and y carbons of amino acids, including racemization, decarboxylations at the a carbon, elimination and replacement reactions at the B andy carbons• PLP is seen bound covalently to the active sites of aminotransferases via structure determination. • The reaction occurs via a typical ping-pong mechanism: the first product leaves before the second substrate enters. • An interconversion between an aldimine（醛亚胺） and a ketimine（酮亚胺） is proposed to occur via a quinonoid（醌型的） intermediate during the transamination reaction. • PLP act in a variety of other reactions at the a, b, and g carbons of amino acids, including racemizations, decarboxylations at the a carbon, elimination and replacement reactions at the b and g carbons