The conformational effect of form I helical poly(L‐proline) and form II helical poly(L‐proline) to the complex formation with helical poly(L‐glutamic acid) through hydrogen bonding

Abstract

AbstractThe complex formation between helical poly‐L‐glutamic acid (PLGA) and helical poly‐L‐proline (PLP) was studied in a methanol‐water (2 : 1) cosolvent and a propanol‐water cosolvent (9 : 1). Reduced viscosity, circular dichroism, pH, and molar absorptivity were measured. The experimental results exhibit that the interpolymer complex was formed between helical PLGA and helical PLP through hydrogen bonding. When the complex was formed the unit mole ratio of PLGA : PLP(II) is 2 : 1 and PLGA : PLP(I) is 1.5 : 1, the ability of complex formation of PLP (II) with PLGA is better than that of PLP(I). On complexation the conformations of PLGA and PLP change and this change is more enhanced in the PLGA‐PLP(II) than the PLGA‐PLP(I) complex; its cause is studied. © 1993 John Wiley & Sons, Inc.