We presented a newly developed set of transferable atom-centered charges and isotropic dipole-dipole polarizabilities (CP 3 ), suitable for use in PE-based calculations involving protein environments. The set of parameters covers all standard amino acids, including alternate side-chain protonation states. The parameters are amino-acid specific and were derived by simultaneously fitting to the static or induced EPs of a large set of configurations sampled from a backbone-dependent rotamer library. The fitting was performed by minimizing a cost function that contains a probability-weighted sum of contributions from all of the included configurations. We showed that the CP 3 yields consistent accuracy across a wide set of structures, ranging from a series of tripeptides to a series of small proteins, by comparing CP -based EPs to references computed using a high-level quantum-mechanical method. In terms of reproducing EPs, the CP 3 outperforms the AMBER ff94 force field mainly due to the inclusion of explicit polarization but performs slightly worse than the polarizable AMOEBA and MFCC-based M2P2 potentials. The main reason for the higher accuracy of the latter potentials was identified to be the inclusion of higher-order multipoles.