Skip to main content
. Author manuscript; available in PMC: 2011 Feb 1.
Published in final edited form as: Nat Chem Biol. 2010 Jun 27;6(8):602–609. doi: 10.1038/nchembio.402

Figure 2.

Figure 2

UV-visible spectra of complexes of Scn-Ngal, siderophores, and iron. (a) apo-Scn-Ngal, Ent:ironIII and Scn-Ngal:Ent:ironIII (left) and apo-Scn-Ngal, catechol:ironIII, and Scn-Ngal:catechol:ironIII (right). While ligand-metal charge-transfers between Ent and ironIII (λmax = 498 nm) were not modified by the addition of Scn-Ngal protein (note red coloration in B, 2 left tubes), catechol:ironIII converted from a FeL complex (blue, λmax = 575 nm) to a FeL3 complex (red, λmax = 498 nm) when bound to Scn-Ngal (b, right tubes). (c) Speciation diagram of catechol:ironIII (10:1) in solution. FeL2 was the predominant species at pH 7.4. FeL3 may be observed in more basic conditions. The speciation diagram was calculated in HySS (Hyperquad Simulation and Speciation) based on catechol thermodynamic values.