Steady-state fluorescence and NMR study on self-association behavior of poly(methacrylamides) bearing hydrophobic amino acid residues

The polymer concentration (Cp) dependencies of association properties of pMPhe and pMTrp at pH≈5 are distinct. Steady-state fluorescence data at varying Cp indicated that pMPhe was more hydrophobic microscopically than pMTrp. Dynamic light scattering data indicated that pMTrp had a stronger tendency for interpolymer association than pMPhe did at pH≈5. It is concluded that the distinction in Cp dependency of the self-association properties of pMPhe and pMTrp is due to the differences in the bulkiness and the hydrophobicity of the substituents of amino acid residues.