. Author manuscript; available in PMC: 2010 Jul 1.

Published in final edited form as: Cell Signal. 2009 Mar 16;21(7):1169–1179. doi: 10.1016/j.cellsig.2009.03.006

Table 2.

Effect of coatomer and cargo on kinetics of GTP hydrolysis

Size of LUVs	0.03 μm			1.0 μm
constant	Coatomer	coatomer+p25	coatomer	coatomer+p25
A₁ (%)	38.1±2.0	60.1±1.4^***	11.9±0.4⁺⁺⁺	24.8±1.1^***,⁺⁺⁺
A₂ (%)	58.8±2.0	35.0±1.4	83.1±0.35	70.24±1.1
k₁ (min⁻¹)	2.3±0.39	6.7±0.87^***	2.2±0.26	1.7±0.29
k₂ (min⁻¹)	0.012±0.0026	0.027±0.005^***	0.005±0.0005	0.004±0.0012

Progress curves from Figure 4 were fit to the 2^nd order rate equation % GTPHydrolyzed = A₁ · (1 − e −^k^₁^t) + A₂ · (1− e⁻^k^₂^t). Reactions contained 0.6 μM [α³²P]GTP•Arf1 as a substrate, LUVs containing PI4P and extruded through 0.03 μm or 1.0 μm pores, 124 nM coatomer and 25 μM p25 peptide as indicated. Values are the means ± SD from three experiments. Three ANOVA analyses (one for each of A₁, k₁ and k₂) followed by Bonferroni post tests were performed.

^***

indicates greater than coatomer without p25, p<0.001.

⁺⁺⁺

indicates less than 0.03 μm vesicles, p<0.001.