► The protein of maize, the pea protein, and two soy proteins were evaluated. ► Dissolution tests at different pH, FT-IR analysis, and shear tests were carried out. ► Proteins became more unfolded and solvated after pH increase. ► Variations in the acidity level did not change the conformation of all proteins. ► Pea protein is a valid alternative to soy, zein is not suitable as a wood adhesive.