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Updated: Aug 21, 2026

Quantitating Iron Transport Across the Mouse Placenta In Vivo Using Nonradioactive Iron Isotopes
Published on: May 10, 2022
Phosphate ester hydrolysis is catalyzed by a bacterial transferrin: potential implications for in vivo iron transport
Suraj Dhungana1, Damon S Anderson, Timothy A Mietzner
1Department of Chemistry, Duke University, P.O. Box 90346, Durham, NC 27708-0346, USA.
Abstract:
Two synergistic anions, p-nitrophenyl phosphate ester (NPP) and SO(4)(2-), were found to form new stable assemblies with Fe(3+) and a bacterial transferrin, FbpA (FbpA=ferric binding protein). Fe(3+)FbpA-SO(4) undergoes rapid anion exchange in the presence of NPP to form Fe(3+)FbpA-NPP. Formation of Fe(3+)FbpA-NPP was found to accelerate the rate of hydrolysis of the bound phosphate ester (k(hyd)=1.6 x 10(-6) s(-1) at 25 degrees C and pH 6.5) by >10(3) fold over the uncatalyzed reaction. These findings suggest a dual function for FbpA in vivo: transport of Fe(3+) across the periplasmic space to the inner membrane in certain gram-negative bacteria and hydrolysis of periplasmic polyphosphates.
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