Elucidation of the substrate specificity, kinetic and catalytic mechanism of adenylosuccinate lyase from Plasmodium falciparum.

Adenylosuccinate lyase (ASL) catalyzes two distinct but chemically similar reactions in purine biosynthesis. The first, exclusive to the de novo pathway involves the cleavage of 5-aminoimidazole-4-(N-succinylcarboxamide) ribonucleotide (SAICAR) to 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) and fumarate and the second common to both de novo and the salvage pathways involves the cleavage of succinyl-adenosine monophosphate (SAMP) to AMP and fumarate. A detailed kinetic and catalytic mechanism of the recombinant His-tagged ASL from Plasmodium falciparum (PfASL) is presented here.