SCHEME 1.

Binding analysis between PMCA and G-actin using the SPR technique. A, binding of solubilized PMCA to immobilized G-actin. G-actin is covalently attached to the CM5 sensor by reactive NH₂ groups using the conventional protocol for activating the carboxyl groups of the surface. Solubilized PMCAs constitute the flowing analyte. C₁₂E₁₀ monomers are in equilibrium with micelles. B, binding of G-actin to immobilized PMCA. Covalently attached PMCA is stabilized on the sensor surface through continuous addition of C₁₂E₁₀. Immobilization is carried out using the same amine coupling procedure described above. G-actin constitutes the flowing analyte and is maintained in the monomeric state by using a running buffer of low ionic strength without Mg²⁺.