來(lái)自國(guó)家納米科學(xué)中心,、復(fù)旦大學(xué)的研究人員在《美國(guó)化學(xué)會(huì)志》（JACS）上合作發(fā)表了題為“Sequence Effects on Peptide Assembly Characteristics Observed by Using Scanning Tunneling Microscopy”的研究論文,，通過(guò)掃描隧道顯微技術(shù)（STM）來(lái)研究氨基酸序列對(duì)多肽組裝結(jié)構(gòu)及其穩(wěn)定性的影響。
圖摘自論文,，表示利用STM進(jìn)行多肽序列識(shí)別結(jié)果
來(lái)自國(guó)家納米科學(xué)中心的研究人員利用STM技術(shù)在單分子水平上研究多肽的組裝及其調(diào)控,，已經(jīng)發(fā)表了一系列的工作。他們?cè)?011年利用STM確認(rèn)了淀粉樣多肽組裝和聚集的核心片段及折疊位點(diǎn),，對(duì)于研究非結(jié)晶蛋白的組裝結(jié)構(gòu)提供了一種新穎的解析方法（Proc. Natl. Acad. Sci. USA, 2011, 108, 19605等）,，但是由于多肽在表面組裝構(gòu)象的多樣性以及吸附穩(wěn)定性的差異，利用STM進(jìn)行多肽中氨基酸序列的識(shí)別仍具有極大的挑戰(zhàn)性,。
在本研究中,，研究人員利用STM結(jié)合分子動(dòng)力學(xué)模擬，研究了氨基酸殘基序列對(duì)嵌段模型多肽在固體表面的吸附構(gòu)象穩(wěn)定性的影響,，發(fā)現(xiàn)STM圖像中的襯度差異與模型多肽中的序列具有關(guān)聯(lián)性,，同時(shí)分子動(dòng)力學(xué)模擬發(fā)現(xiàn)不同氨基酸殘基與石墨表面的結(jié)合能差異與襯度差異也具有一致性，說(shuō)明了多肽序列對(duì)組裝構(gòu)象和組裝特性的影響,，暗示了利用STM進(jìn)行多肽序列識(shí)別的可能性,。此研究有助于深入理解多肽組裝過(guò)程中側(cè)基結(jié)構(gòu)、序列等對(duì)組裝過(guò)程,、組裝驅(qū)動(dòng)力以及組裝結(jié)構(gòu)的影響,。
此工作得到了科技部重大研究計(jì)劃和基金委重大研究計(jì)劃的支持。(生物谷Bioon.com)
DOI: 10.1021/ja307198u
PMC:
PMID:
Sequence Effects on Peptide Assembly Characteristics Observed by Using Scanning Tunneling Microscopy
Xiaobo Mao, Yuanyuan Guo, Yin Luo, Lin Niu,， Lei Liu, Xiaojing Ma, Huibin Wang, Yanlian Yang, Guanghong Wei and Chen Wang.
Homogeneous assemblies of the model peptides at interfaces have been achieved and observed with scanning tunneling microscopy. The dependence of the observed brightness in STM images is analyzed, and the correlation with the peptide residues is proposed. We have also investigated the conformational dynamics of the peptide assemblies adsorbed on a graphene sheet by performing all-atom molecular dynamic simulations in water at 300 K. The simulation results of the two peptide assemblies on graphite surfaces show that R4G4H8 and F4G4H8 peptide assemblies are mostly in β-sheet structure, and the interaction energy of the four different residues with graphite surfaces follows the order of Phe > His > Arg > Gly, consistent with their brightness contrasts in STM images. The insight on the distribution of residue moieties in the peptide assemblies could provide beneficial venues for studying peptide-based interfacial processes such as site-specific interactions between molecular species with peptides.
