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Asymmetric inclusion by de novo designed proteins: Fluorescence probe studies on amphiphilic α-helix bundles

✍ Scribed by Dr. Hisayuki Morii; Kunihiro Ichimura; Hatsuho Uedaira


Book ID
105358588
Publisher
John Wiley and Sons
Year
1991
Tongue
English
Weight
751 KB
Volume
11
Category
Article
ISSN
0887-3585

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✦ Synopsis


Abstract

The inclusion feature and supersecondary structure of the de novo designed proteins which are constructed with several amphiphilic α‐helices and flexible linkage parts were investigated with fluorescence probes. Five types of small proteins (or peptides) have been designed, which are composed of 2, 3, 4, 4, and 6 helices, respectively, and are linked with only linear junctions except for one of 4‐helix proteins. All of these proteins have inclusion ability for hydrophobic fluorophores. Further, by the analysis of fluorescence polarization anisotropy, it was suggested that these proteins include guest molecules in compact helix bundles constructed with about 4 helices. Asymmetric inclusion of both monomer and stacked dimer of acridine orange derivatives was found by means of induced circular dichroism except for the 4‐helix protein with cross‐junction. The chirality of the included dimer proved to be in accordance with the chiral sense of α‐helical coiled‐coil. The 6‐helix protein has especially high efficiency in inclusion for any fluorophores examined in this study and brings about a significant blue‐shift of maximal emission for 8‐anilino‐1‐naphthalenesulfonate.