The resonance Raman intensities for parsley, spinach, and poplar a plastocyanins, blue copper proteins involved in plant photosynthetic electron transport, have been measured at wavelengths throughout the S(Cys) --> Cu charge transfer absorption band centered at 597 nm in an effort to determine the role of amino acid composition on the dynamics of excited-state charge transfer. The resonance Raman spectra of the three plastocyanins exhibit vibrational bands with similar frequencies but different relative intensities. Self-consistent analysis of the absorption band and resulting resonance Raman excitation profiles for each of the plastocyanins demonstrates that many of the derived molecular parameters are similar, including the zero-zero energy, the transition moment, and the homogeneous and inhomogeneous linewidths. However, significant differences are observed in the mode-specific excited-state geometry distortions even though the total, mode-specific reorganization energy obtained from the resonance Raman intensities of specific vibrations is 0.18 +/- 0.01 eV for all three plastocyanins. A detailed comparison of the structural and electrostatic differences in spinach and poplar a plastocyanin using the previously reported structure of poplar a plastocyanin, potential energy minimization, and calculation of the electrostatic field with the linearized Poisson-Boltzmann equation suggests that the mode-specific relative intensity differences arise from a change in the normal mode description due to differential coupling of internal coordinates localized on amino acid residues at least 8 Angstrom from the copper site. These results demonstrate that the protein environment is strongly coupled to the copper site and that a significant portion of the protein, which is not involved in binding of redox partners, determines the copper site coordination geometry and resulting redox potential. An important result is that the mode-specific protein component of the reorganization energy on the 20 fs time scale is sensitive to protein composition differences that are at least 8 Angstrom from the charge transfer site.