As part of our ongoing project that aims at the optimum characterization of the electronic structure of the blue-copper site of azurin from Pseudomonas aeruginosa, we present the complete hyperfine tensors of the protons bound to the Cbeta atom of the copper-bound cysteine 112. These tensors have been obtained from a 95 GHz pulsed electron-nuclear double resonance study of a single crystal of the protein.