TY - JOUR
T1 - Low-flux scanning electron diffraction reveals substructures inside the ordered membrane domain
AU - Kinoshita, Masanao
AU - Yamaguchi, Shimpei
AU - Matsumori, Nobuaki
N1 - Funding Information:
We thank Prof. Satoru Kato (Kwansei-Gakuin University, Hyogo, Japan) for their approval of use of electron microscope for LFSED experiments and useful discussion about analysis of the electron diffraction patterns. The other electron microscopic observations were conducted at Ultramicroscopy Research Center (Kyusyu University, Fukuoka, Japan). This work was supported in part by Grants-in-Aid for scientific research from the Japan Society for the Promotion of Science (Wakate B and Kiban C) to Masanao Kinoshita [17K15107 and 20K06590, respectively]. We would like to thank Editage (http://www.editage.com) for English language editing.
PY - 2020/12
Y1 - 2020/12
N2 - Ordered/disordered phase separation occurring in bio-membranes has piqued researchers’ interest because these ordered domains, called lipid rafts, regulate important biological functions. The structure of the ordered domain has been examined with artificial membranes, which undergo macroscopic ordered/disordered phase separation. However, owing to technical difficulties, the local structure inside ordered domains remains unknown. In this study, we employed electron diffraction to examine the packing structure of the lipid carbon chains in the ordered domain. First, we prepared dehydrated monolayer samples using a rapid-freezing and sublimation protocol, which attenuates the shrinkage of the chain-packing lattice in the dehydration process. Then, we optimised the electron flux to minimise beam damage to the monolayer sample. Finally, we developed low-flux scanning electron diffraction and assessed the chain packing structure inside the ordered domain formed in a distearoylphosphatidylcholine/dioleoylphosphatidylcholine binary monolayer. Consequently, we discovered that the ordered domain contains multiple subdomains with different crystallographic axes. Moreover, the size of the subdomain is larger in the domain centre than that near the phase boundary. To our knowledge, this is the first study to reveal the chain packing structures inside an ordered domain.
AB - Ordered/disordered phase separation occurring in bio-membranes has piqued researchers’ interest because these ordered domains, called lipid rafts, regulate important biological functions. The structure of the ordered domain has been examined with artificial membranes, which undergo macroscopic ordered/disordered phase separation. However, owing to technical difficulties, the local structure inside ordered domains remains unknown. In this study, we employed electron diffraction to examine the packing structure of the lipid carbon chains in the ordered domain. First, we prepared dehydrated monolayer samples using a rapid-freezing and sublimation protocol, which attenuates the shrinkage of the chain-packing lattice in the dehydration process. Then, we optimised the electron flux to minimise beam damage to the monolayer sample. Finally, we developed low-flux scanning electron diffraction and assessed the chain packing structure inside the ordered domain formed in a distearoylphosphatidylcholine/dioleoylphosphatidylcholine binary monolayer. Consequently, we discovered that the ordered domain contains multiple subdomains with different crystallographic axes. Moreover, the size of the subdomain is larger in the domain centre than that near the phase boundary. To our knowledge, this is the first study to reveal the chain packing structures inside an ordered domain.
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U2 - 10.1038/s41598-020-79083-7
DO - 10.1038/s41598-020-79083-7
M3 - Article
C2 - 33349660
AN - SCOPUS:85097945266
SN - 2045-2322
VL - 10
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 22188
ER -