. Author manuscript; available in PMC: 2015 Jul 17.

Published in final edited form as: J Biol Inorg Chem. 2010 Aug 14;15(8):1341–1352. doi: 10.1007/s00775-010-0694-2

Table 4.

Rate constants for iron release from Fe_ChTF and His349 Fe_ChTF mutants bound to the glycosylated, N-terminal hexa-His-tagged soluble recombinant transferrin receptor (residues 121–760) (sTFR)

Construct (Fe_ChTF + sTFR)	Conformational event k₁ (min⁻¹)^a	Fold difference control	Iron release k₂ (min⁻¹)^a	Fold difference control
Control^b (N = 32)	20.6 ± 1.2	–	7.2 ± 0.4	–
H349A (N = 5)	9.2 ± 0.8	2.2 × slower	1.4 ± 0.5	5 × slower
H349D^c (N = 3)	11.3 ± 1.6	1.8 × slower	–	–
H349K (N = 5)	1.9 ± 0.2	10.8 × slower	1.9 ± 0.2	4 × slower
H349L (N = 3)	14.4 ± 0.8	1.4 × slower	1.8 ± 0.8	4 × slower
H349W (N = 3)	–	–	5.9 ± 1.6	1.2 × slower
H349Y (N = 3)	–	–	5.6 ± 0.6	1.3 × slower

Averages and 95% confidence intervals for kinetic runs performed on N = 3–32 different days. Each day three kinetic traces were averaged before fitting

From [6]

Note that not all the iron was removed from the H349D mutant, as indicated by urea gel analysis (Fig. 1b)