The attachment of a nonlinear optical chromophore to a polypeptide backbone yields a structure in which the chromophores are oriented non-centrosymmetrically, likely due to the supramolecular helix structure of the polypeptide. This structure exhibits enhanced nonlinear optical properties and can be easily poled in an electrostatic field. The result demonstrates the great potential of supramolecular engineering for optimizing NLO properties.