Open AccessVisualization of the Orientation of Amphipathic Peptides at the Air–Water Interface by X-Ray Reflectometry
Author(s) -
Mari Okuno,
Makoto Itagaki,
Teru Ishibashi,
Yohko F. Yano
Publication year - 2021
Publication title -
analytical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 73
eISSN - 1348-2246
pISSN - 0910-6340
DOI - 10.2116/analsci.21p068
Subject(s) - chemistry , monolayer , reflectometry , electron density , helix (gastropod) , x ray reflectivity , crystallography , adsorption , x ray , analytical chemistry (journal) , reflectivity , electron , optics , chromatography , biochemistry , time domain , ecology , physics , quantum mechanics , snail , computer science , computer vision , biology
X-ray reflectivity measurements were performed for the leucine and lysine-based LKα14 peptide designed to adopt an α-helical conformation at the air-water interface. The electron density profiles along the surface normal were calculated from the atomic coordinates predicted by an electronic structure program to fit the X-ray reflectivity curve. At the concentration of the monolayer formation, the long axis of the α-helix adsorbed parallel to the water surface, and the central part was revealed to be submerged in water. On the other hand, at 100 times higher than the surface area density of the monolayer formation, the double layer is formed in which the long axis of the α-helix is parallel to the water surface and only the peptide in the second layer is submerged in water.