Can Complete Transporter Mechanisms be Inferred from Experimental Data?

Abstract

Membrane cotransporters perform essential cellular functions, selectively transporting nutrients as well as maintaining ion concentration gradients. Although careful structural, biochemical, and electrophysiological studies have revealed important elements of transporter mechanisms, numerous aspects remain ambiguous. Generally, the precise order of binding events is unknown, and it remains an open question whether multiple mechanistic pathways are at play. Here we address the identifiability question: Which mechanistic details can be resolved in principle based on both typical and idealized experimental data? Our approach builds on previous work to search and fit models using the entire allowed transporter reaction and state space.