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Ammonia permeability of the soybean nodulin 26 channel
Author(s) -
Hwang Jin Ha,
Ellingson Sally R.,
Roberts Daniel M.
Publication year - 2010
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2010.09.033
Subject(s) - aquaporin , biophysics , ammonia , chemistry , efflux , biochemistry , water transport , permeability (electromagnetism) , membrane transport , microbiology and biotechnology , membrane , biology , water flow , environmental engineering , engineering
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.