TABLE 3.

The binding kinetics of BiP and DnaK for the NR peptide

	k obs (×10−3/s)
	BiP		DnaK
	pH 4.5	pH 7.0	pH 4.5	pH 7.0
ATP	ND	6.759 ± 0.218	ND	ND
ADP	81.0 ± 4.8	0.693 ± 0.018	12.5 ± 1.4	9.25 ± 1.14
AMP	35.1 ± 6.7	0.576 ± 0.007	7.51 ± 0.45	6.30 ± 0.52
Apo	55.6 ± 5.8	0.628 ± 0.055	20.0 ± 3.3	5.62 ± 0.44

Note: The binding kinetics (k _obs ) were determined using the fluorescence polarization assay with the NR peptide labeled with fluorescein at two different pH conditions, 4.5 and 7.0. The binding in the absence of nucleotide was used as a control (Apo). ND: not determined due to the kinetics were too fast to calculate for our instrument. The k _obs values were mean ± SEM determined from three independent experiments using more than two different protein purifications. One representative of the corresponding binding curves for each condition was shown in Figure S8.

Abbreviation: BiP, Binding immunoglobin protein.