文章基本信息

标题：Energetics of side-chain snorkeling in transmembrane helices probed by nonproteinogenic amino acids
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作者：Karin Öjemalm ; Takashi Higuchi ; Patricia Lara 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2016
卷号：113
期号：38
页码：10559-10564
DOI：10.1073/pnas.1606776113
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Cotranslational translocon-mediated insertion of membrane proteins into the endoplasmic reticulum is a key process in membrane protein biogenesis. Although the mechanism is understood in outline, quantitative data on the energetics of the process is scarce. Here, we have measured the effect on membrane integration efficiency of nonproteinogenic analogs of the positively charged amino acids arginine and lysine incorporated into model transmembrane segments. We provide estimates of the influence on the apparent free energy of membrane integration (ΔGapp) of “snorkeling” of charged amino acids toward the lipid–water interface, and of charge neutralization. We further determine the effect of fluorine atoms and backbone hydrogen bonds (H-bonds) on ΔGapp. These results help establish a quantitative basis for our understanding of membrane protein assembly in eukaryotic cells.
关键词：membrane protein ; nonproteinogenic amino acids ; translocon