title: Effect of non-native helix destabilization on the folding of equine β-lactoglobulin.
abstract: β-lactoglobulin forms a non-native α-helix during an early stage of folding. To address the role of the non-native structure in the folding process, we designed several mutants of equine β-lactoglobulin with reduced helical propensity in the non-native helix region. One of them, A123T, showed a similar structure to that of the wild-type protein; its folding kinetics was investigated by stopped-flow circular dichroism (CD) and fluorescence. Although A123T showed a reduced burst-phase CD intensity, its folding rate was similar to that of the wild-type protein, which indicated that the formation of the non-native helix does not accelerate or decelerate the folding reaction.
authors.affiliation: Department of Bioinformatics, Soka University, 1-236 Tangi-Machi, Hachioji, Tokyo 192-8577, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Okabe
authors.affiliation: Department of Bioinformatics, Soka University, 1-236 Tangi-Machi, Hachioji, Tokyo 192-8577, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Miyajima
authors.affiliation: Department of Bioinformatics, Soka University, 1-236 Tangi-Machi, Hachioji, Tokyo 192-8577, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Nakagawa
authors.affiliation: Department of Bioinformatics, Soka University, 1-236 Tangi-Machi, Hachioji, Tokyo 192-8577, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Tsukamoto
authors.affiliation: Department of Bioinformatics, Soka University, 1-236 Tangi-Machi, Hachioji, Tokyo 192-8577, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Fujiwara
authors.affiliation: Department of Bioinformatics, Soka University, 1-236 Tangi-Machi, Hachioji, Tokyo 192-8577, Japan ikeguchi@soka.ac.jp.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Ikeguchi
mesh_terms: D000818:Animals; D002942:Circular Dichroism; D006736:Horses; D007700:Kinetics; D007782:Lactoglobulins / Q000737:chemistry* / Q000235:genetics; D009154:Mutation; D017510:Protein Folding; D017433:Protein Structure, Secondary
chemical_list: D007782:Lactoglobulins
keywords: circular dichroism; fluorescence; folding intermediate; helical propensity; stopped flow