Figure 1.

ITIR-FCS data of Lti30 binding with supported lipid bilayers. The effect of Lti30 on lipid mobility in supported lipid bilayers composed of different compositions and at pH 5.8, 6.3, 7.4, and 9.0 was measured. The measurements were performed at a region of 21 × 21 pixels in the form of 50,000 frames at a time exposure of 1 ms. The measurements were done up to 40 min after the addition of Lti30 over the membrane. Membrane lipid diffusion is quantified using two parameters diffusion coefficient (D) and diffusion law intercept (τ₀). The protein–to–lipid ratio used is 1:130. A, DOPC; B, DOPC:DOPS (4:1); C, DOPC:DPPC (1:1). Error bars are given as standard deviations (S.D.). The experiments have been repeated three times to ensure the reproducibility. The gray-shaded area in τ₀ graphs represents the range of margin of error in our setup (−0.1 s < 0 < 0.1 s) in which the particle is considered to undergo free diffusion. For representative raw data see Figs. S1–S3.