短いアラニンペプチドにおける水分子の吸収:最も短いガス相のアラニン基ヘリクスはどのくらい短いか?

Motoya Kohtani¹, Martin F Jarrold

¹Chemistry Department, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, USA.

Journal of the American Chemical Society

|July 9, 2004

まとめ

水吸収は,明確なペプチド構造を明らかにします. アラニンペプチド (Ac-A(n) K+H(+)) は,n=8の辺りで螺旋状の形状に変化し,球状の形状とは異なり,水吸収が低下している.

科学分野:

化学物理化学物理
バイオ物理化学バイオ物理化学
スペクトル顕微鏡検査です.

背景:

ペプチド構成は,水との相互作用に影響する.
以前の研究では,アラニンペプチドの螺旋状および球状状態を特定しました.
水吸収強度は,これらの形状の間で著しく変化します.

研究の目的:

溶解されていないAc-A(n) K+H(+) とAc-KA(n) +H(+) ペプチドの水吸収を調査する.
アラニン,バリン,ルシンペプチドの構造転換点を決定する.
ガス相におけるペプチド二次構造と水の吸収傾向を相関させるため.

主な方法:

均衡状態の水吸収測定.
ペプチド-水複合体を分析するための質量スペクトロメトリ.
アラニン,バリン,ルシンペプチドのペプチド鎖の長さが異なる (n=4-10).

主要な成果:

Ac-KA(n) +H(+) ペプチド (球状) は,強い水吸収を示した.
Ac-A(n) K+H(+) ペプチドは,n<8.8で強く水に吸収される.
n=8-10でAc-A(n) K+H(+) の吸水率の有意な低下は,螺旋的な移行を示しています.

結論:

螺旋構造は,n=8.8でAc-A(n) K+H(+) ペプチドで発生する.
ヘリックス形成は,Ac-V (n) K+H (n) +) とAc-L (n) K+H (n) +) ペプチドのn=8で示唆されています.
水吸収は,ガス相ペプチド構成の敏感な探査機である.

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