L-Canaline Detoxification: A Seed Predator's Biochemical Mechanism.

The seeds of the Neotropical legume, Dioclea megacarpa, the sole food source for developing larvae of the bruchid beetle, Caryedes brasiliensis, contain about 13 percent L-canavanine (dry weight). Canavanine detoxification and utilization produces L-canaline, a potent neurotoxic and insecticidal amino acid. This seed predator has developed a unique biochemical mechanism for degrading canaline by reductive deamination to form homoserine and ammonia. In this way, canaline is detoxified; canavanine's stored nitrogen is more fully utilized and its carbon skeleton is conserved.