MALDI mass spectrometric determination of dendritic iron chelation stoichiometries and conditional affinity constants.
The iron chelation stoichiometries of a dendritic iron(III) chelator with N(1), N(3), N(5)-trimethylbenzene-1,3,5-tricarboxamide at its core, and containing 3 identical hexadentate tris-hydroxypyridinone branches D was studied by MALDI mass spectrometry. At pH 7.2, the speciation of the system included FeD, Fe(2)D and Fe(3)D species with the respective conditional stability constants of 26.74, 26.03 and 25.36. The differences in the stepwise affinity constants arise from the statistical distribution of iron(III), and there was no evidence for cooperativity between the iron-binding sites.
Kong
Xiaole
X
Division of Pharmaceutical Science, King's College London, UK.
Neubert
Hendrik
H
Zhou
Tao
T
Liu
Zu Dong
ZD
Hider
Robert C
RC
D001665:Binding Sites; D003198:Computer Simulation; D007502:Iron Chelating Agents / Q000737:chemistry*; D008956:Models, Chemical; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D007502:Iron Chelating Agents