Logo

上海交通大学自然科学研究院最新成果:生物膜插入的机制

近期,国际顶级学术期刊自然杂志子刊Nature Communications发表了上海交大自然科学研究院及物理系特别研究员Jakob Ulmschneider及合作者题为“Spontaneous transmembrane helix insertion thermodynamically mimics translocon-guided insertion”的论文(2014年9月 10号,Nat. Comm.), 报道了他们关于生物膜alpha-helix插入的机理研究的最新进展。Nature Communications为科学界影响力最高的交叉科学综合性期刊之一,涵盖物理、 化学、生物、等科学领域。

参考文献:” Spontaneous transmembrane helix insertion thermodynamically mimics translocon-guided insertion”

The favourable transfer free energy for a transmembrane (TM) α-helix between the aqueous phase and lipid bilayer underlies the stability of membrane proteins. However, the connection between the energetics and process of membrane protein assembly by the Sec61/SecY translocon complex in vivo is not clear. Here, we directly determine the partitioning free energies of a family of designed peptides using three independent approaches: an experimental microsomal Sec61 translocon assay, a biophysical (spectroscopic) characterization of peptide insertion into hydrated planar lipid bilayer arrays, and an unbiased atomic-detail equilibrium folding-partitioning molecular dynamics simulation. Remarkably, the measured free energies of insertion are quantitatively similar for all three approaches. The molecular dynamics simulations show that TM helix insertion involves equilibrium with the membrane interface, suggesting that the interface may play a role in translocon-guided insertion.