Fig. 3.

Fluorescence spectra of the thiol-reactive probes. (A) Technical fluorescence excitation spectrum of the G-actin conjugate of compound 12, showing the S₀ - S₂ (centered at 370 nm) and S₀ - S₁ (centered at 558 nm) excitation bands of MC. The emission was monitored at an emission wavelength of 650 nm. (B) Normalized, technical emission spectra of G-actin conjugates of the following compounds: curve a, compound 3 (624 nm); curve b, compound 12 (622 nm); curve c, compound 6 (628 nm); and curve d, compound 13 (630 nm). The emission from the MC state in each conjugate was generated by using an excitation wavelength of 370 nm.