抄録
We prepared amphiphilic peptide, (L-Leu-L-Lys)8, grafted poly(N-isopropylacrylamide) crosslinked membranes which have the pH and thermo-responses in the MF-Millipore support films. The content of grafted peptide was fixed at 4 mol% and the crosslinking degrees of the membranes were 1.5% and 16%, respectively. We investigated the influence of the crosslinking degree on the pH and thermo-induced permeability and permselectivity of L- and D-Phe through the membranes. Under the neutral condition (pH 6.5, at 20 °C), the maximum permselectivity (α=2.6) and relatively high permeability (P=2.86×10-7 cm2 s-1) were achieved in the high crosslinking degree membrane (16%). Meanwhile, the low crosslinking degree membrane showed very high permeability (P=3.2×10-6 cm2 s-1) under this condition. In the high crosslinking degree membrane, the peptide graft chains formed β-sheet domain. The domain acted as the selective permeable path for L-Phe. On the other hand, In the low crosslinking membrane, the grafted peptide chains, which were fixed on the flexible poly(N-isopropylacrylamide) main chains, could not form the β-sheet domain result in the high permeability and low perselectivity of the Phe.
