Effects of Tyrosyl Residue on the Polypeptide Monolayers

概要

論文の詳細を見る
The monolayers of poly-DL-phenylalanine (I), poly-L-tyrosine (II), copoly-1:1-(L-tyrosine, L-phenylalanine) (III), copoly-1:1: 2-(L-tyrosine, o-benzyl-L-tyrosine, L-phenylalanine) (IV), and copoly-1: 1-(L-tyrosine, glycine) (V) have been investigated at the air/water and oil/water interfaces. The surface moment of I decreased by 50∼60 mD more on alkaline than on the acid subphase, probably owing to the keto-enol transformation of the peptide bond. The decrease in the surface moment of II is about 100 mD; this decrease seems to be caused by the ionization of the side chains and by the enolation of the peptide bond. At the air/water interface, the effects of the dissociation of the tyrosyl residue on the II-A relations of II, III, IV and V were not very remarkable, probably because of the peptenol effect and the van der Waals force between side chains. It was found that the monolayers of I, II, III and IV assume a β-configuration. On the other hand, the film of V occupies much less area per residue than those in the β-form, which might be attributed to the folded structure caused by the strong intrachain hydrogen bond due to the glycyl residue. At the oil/water interface, the films of I, III and V expand more and the change in subphase pH seems to be more effective than at the air/water interface. These facts might be caused by the release of van der Waals force between the side chains.
社団法人日本化学会の論文