MS in Chemistry student Natalie Schultz, along with professional research assistant Nara Chon (MS Chemistry 2018) and Hai Lin, Professor of Chemistry, co-published a paper in the Journal of Chemical Information and Modeling on research of an ion transport protein called NarK. The paper is titled “Anion pathways in the NarK nitrate/nitrite exchanger." Their research notably shed light on a long-standing puzzle: NarK stops functioning upon a seemingly harmless arginine-to-lysine mutation in the binding site, which perfectly preserves the positive charge needed for recruiting the negatively charged anion. Their modeling suggests that the mutation can trap the anion in the pore, disrupting the transport cycle. The study underscores pK_a (a measure of how acidic a molecule is) of key residues in fine tuning the function of the protein. “Yes, charge is critical,” said Schultz, “but it is not the whole story, because pK_a matters, too!” Here's the link to the paper.