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Updated: Jun 8, 2026

Membrane Transport Processes Analyzed by a Highly Parallel Nanopore Chip System at Single Protein Resolution
Published on: August 16, 2016
Ammonia permeability of the soybean nodulin 26 channel
Jin Ha Hwang1, Sally R Ellingson, Daniel M Roberts
1Graduate School of Genome Science and Technology, The University of Tennessee-Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
Abstract:
Soybean nodulin 26 (nod26), a member of the aquaporin superfamily, is the major protein component of the symbiosome membrane that encloses nitrogen-fixing bacteroids in root nodules. Previous work has demonstrated that nod26 facilitates the transport of water and glycerol, although a potential additional role as a channel for fixed ammonia efflux has been hypothesized. In the present study it is shown that recombinant nod26 reconstituted into proteoliposomes facilitates NH(3) transport in an Hg(2+)-sensitive manner with a reduced activation energy, hallmarks of protein-facilitated transport characteristic of aquaporins. Comparison of the predicted single-channel transport rates of nod26 suggests a 4.9-fold preference for ammonia compared to water.
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