TABLE 4.

Isothermal titration calorimetry of Rab-effector complexes

The direction of arrows indicates the injection of titrant. For example, wtRCP(581–649) was injected into Rab14(2–175); thus, the stoichiometry is interpreted as RCP-Rab14 = 1.6:1. The numbers are the average of at least two independent experiments.

	Kd	ΔH	ΔS	Stoichiometry
	μm	kcal/mol	cal/K
Rab11(GTP)
→MBP-FIP2a	0.25 ± 0.05	−10.4 ± 1.5	−4.8 ± 0.8	1.0 ± 0.1
←wtRCP(581–649)	1.1 ± 0.2	−9.1 ± 1	−3.8 ± 0.8	1.0 ± 0.2
Rab14(2–175)(GTP)
→MBP-FIP2	2.3 ± 0.3	−5.3 ± 0.8	7.9 ± 1.2	0.44 ± 0.1
←wtRCP(581–649)	1.8 ± 0.3	−5.5 ± 0.9	7.4 ± 1.5	1.6 ± 0.3
Rab25(7–180)(GTP)
→MBP-FIP2	0.65 ± 0.07	−6.4 ± 0.5	6.6 ± 0.7	1.1 ± 0.2
←wtRCP(581–649)	1.4 ± 0.3	−6.5 ± 0.2	4.6 ± 1	1.1 ± 0.2

^a These data were extracted from a previous study by the authors (26). The Rab25(7–180) construct is also described in this paper.