The molecules developed by Johnson and one of his graduate students, Jake Vickaryous of Portland, are known as a chelators (pronounced “kee-lay-tor,” from the Greek chele, meaning “crab claw”). A chelator's molecular configuration and binding sites enable it to trap and immobilize a heavy metal atom. In this case, a sulfur-based molecule was synthesized. In the presence of a toxic form of arsenic, three of these molecules bond with two arsenic atoms to create a triangular, pyramid-like molecular structure.
“By improving our understanding of these chemical interactions, we hope to develop more effective remediation agents - molecules that can do the work of rendering arsenic harmless,” Johnson says. Although they've demonstrated their new molecule can encapsulate arsenic in a laboratory setting, Johnson says, the challenge of treating poisoned individuals remains. The next step is to verify that the new molecule can render arsenic harmless without creating new problems in the human body. “We're now trying to prove that our molecule wants arsenic more than things in your body want arsenic.”