Table 1. Thermodynamic parameters of the interaction of syntaxins and SM proteins measured by ITC
Interaction ofKd (nM)ΔH° (kcal/mole)n
Syx1a (1–262)/Munc18a1.4±0.3−34.6±0.21.03
Syx1a (1–240)/Munc18a2.7±0.6−34.3±0.41.01
Syx1a (1–226)/Munc18a621.1±107.2−8.0±0.50.84
Syx1a (1–179)/Munc18a693.9±84.2−5.5±0.50.91
Syx1a (1–20)/Munc18a
Syx1a (25–262)/Munc18a8.1±1.0−25.1±0.21.01
Syx1a (180–262)/Munc18a
Syx1a (180–262)+Syx1a (1–179)/Munc18a277.8±33.7−21.2±0.80.94
Syx1aLE/Munc18a7.7±0.6−34.8±0.20.99
Syx1aI233A/Munc18a333.3±58.4−16.0±0.70.93
Syx1aR4A/Munc18a9.4±1.6−27.3±0.31.03
Syx1aT5A/Munc18a1.9±0.7−32.6±0.31.01
Syx1aL8A/Munc18a9.1±1.7−27.3±0.31.01
Syx1aT10A/Munc18a0.4±0.2−34.6±0.21.05
Syx1aS14A/Munc18a2.6±1.3−33.5±0.41.03
SNARE complex containing Syx1a (1–262)/Munc18a719.4±118.0−4.8±0.40.84
SNARE complex containing Syx1a (25–262)/Munc18a
Syx16 (1–302)/Vps452.1±1.2−23.8±0.21.09
Syx16 (1–279)/Vps450.85±0.3−26.3±0.10.96
Syx16 (1–265)/Vps4511.7±3.6−13.6±0.21.07
Syx16 (1–183)/Vps4532.5±0.3−12.0±0.10.93
Syx16 (1–27)/Vps4526.9±0.3−11.6±0.10.95
Syx16 (1–27)F10A/Vps45
Syx16 (1–302)F10A/Vps45116.6±16.5−15.6±0.50.85
Syx16 (28–302)/Vps45
  • All isothermal calorimetric experiments were performed at 25°C in PBS buffer. The experimental ITC data for the interaction of Munc18a and syntaxin 1a variants and for Vps45 and syntaxin 16 variants are shown, respectively, in Supplementary Figures 6 and 7.