Two tricopolypetides with varying amounts of glycyl, ϵ-carbobenzoxy-L-lysyl, and γ-benzyl-L-glutamyl residues were synthesized and characterized by determining their intrinsic viscosity, refractive index increment, molecular weight, and second virial coefficient in the random coil solvent dichloraoacetic acid. The characteristic ratio (C∞) of the two polypetides was determined using the Brant-Flory equation. C∞ decreased from 8.1 to 4.8 on changing the content of glycine from 27.3 to 46.0 mole %. These values of C∞ are markedly higher than those expected from a consideration of the effect of glycine on random coil dimensions of copolypeptides.