D-homoserine lactone is an enantiomer of L-homoserine lactone and an inhibitor of serine hydroxymethyltransferase (SHMT; Ki= 11 mM for the rabbit enzyme).1 1.Wang, E.A., Kallen, R., and Walsh, C.Mechanism-based inactivation of serine transhydroxymethylases by D-fluoroalanine and related amino acidsJ. Biol. Chem.256(13)6917-6926(1981)