Figure 8
From: Complex approach for analysis of snake venom α-neurotoxins binding to HAP, the high-affinity peptide
ESI-MS observation of the toxin and binding peptide combined mass. (A) superimposed spectra of 1:1 αCtx to HAP[L9E] mixture (background spectrum) and 1:10 αCtx to HAP[L9E] mixture (foreground spectrum). Note that m/z peaks (pointed by red arrows) indicating the combined αCtx + HAP[L9E] mass are higher in the 1:10 than in 1:1 mixture. Titration of αCtx/αBgt with HAP/HAP[L9E] and monitoring the intensities of the respective peaks allows the binding evaluation. (B) Titration curves fitted by the one-site binding equation: αBgt and HAP (red), αBgt and HAP[L9E] (magenta), αCtx and HAP[L9E] (blue), αCtx and HAP (green). Even though both αCtx curves do not saturate at 100% (in contrast to αBgt), complex HAP[L9E] saturates at a higher level (73 + 3%) than HAP (37 + 8%), indicating stronger binding between the toxin and mutated peptide. Drawings showing 3D structures were prepared with the UCSF Chimera, version 1.12 (http://www.rbvi.ucsf.edu/chimera/).
