Lipid Nanotube Encapsulating Method in Low-Energy Scanning Transmission Electron Microscopy Analyses

Abstract

The lipid nanotube (LNT) encapsulating method is a rational sample fixation method that can be used to mount samples for transmission electron microscopy analyses. By employing the LNT encapsulating method in 30 kV low-voltage scanning transmission electron microscopy (LV-STEM), it is possible to record multiangle images of ferritin without using the negative staining method. We have also recorded a tilted series of high-contrast LV-STEM images and reconstructed three-dimensional images. These results show that LNTs have sufficient durability for LV electron beam, and indicate the potential of the LNT encapsulating method as a sample fixation method of LV electron microscopy. #

Supramolecular organic nanotubes: how to utilize the inner nanospace and the outer space

“…These advantages of the nanotubes' hollow cylinders allowed us to develop a new TEM analysis method for proteins. 119,120 Asymmetrical nanotubes formed from 1-( 18) functioned as a sample-fixation matrix for protecting target proteins from drying and freezing conditions. Moreover, the cylindrical shape of the nanotubes improved TEM computed tomography analysis, which suffers from the loss of the electron beam at high tilting angles based on the increased effective thickness of a common supporting film as a fixation matrix.…”

Soft-Matter Nanotubes: A Platform for Diverse Functions and Applications

“…35,36 Moreover, one recent outstanding advance in new functions that will take place in the interior nanospace is the utilization of a multiwalled LNT as a sample fixation substrate for transmission electron microscopy (TEM) computed tomography (CT). 116,117 It should also be noted that catalytic actions, conducted by metal-coordinated SMNTs 118−122 and MONNs prepared from BBC, 84 give another special examples. Some SMNTs act as chemical nanoreactors by using confined nanospace.…”

“…Furusho and co-workers exploited a novel approach to employ the glycolipid LNTs consisting of multiple lipid bilayer membranes as a samplefixation substrate. 116,117 Advantages of the discrete LNT over any other tubular nanomaterials can be found in the controllability over the size, dimension, and shape of the nanotube as well as versatile functionalization of surfaces. Using globelike proteins [e.g., ferritin (diameter = 12 nm) and DNA-binding protein from starved cells as a ferritin superfamily (diameter = 9 nm)], they succeeded in the reconstruction of 3-D images of Fe cores from electron energy-loss spectroscopy mapping images or from zero-loss images.…”

“…A typical example was shown by the fact that optimized inner surfaces of SMNTs and the exterior functionalities of a guest protein enable some SMNTs to behave as artificial molecular chaperone. , Moreover, one recent outstanding advance in new functions that will take place in the interior nanospace is the utilization of a multiwalled LNT as a sample fixation substrate for transmission electron microscopy (TEM) computed tomography (CT). , It should also be noted that catalytic actions, conducted by metal-coordinated SMNTs − and MONNs prepared from BBC, give another special examples. Some SMNTs act as chemical nanoreactors by using confined nanospace. ,,, PRNTs with α-glucosidase or lipase B interior surfaces, obtained by a template method, displayed the activity as an enzymatic channel reactor in a similar manner. , Of great interest in novel release function is that O 2 bubbles jetting from an opened end of the PRNT can self-propel the tube itself in aqueous media and behave as a micron size engine. , …”

“…To overcome a significant problem of the electron beam loss due to the interaction of a supporting film interception in tilted observation at high angles, several approaches have utilized the external or inner surfaces of hollow cylindrical architectures including CNTs, LNTs, and vesicular tubules, , as a substrate of samples for TEM. Furusho and co-workers exploited a novel approach to employ the glycolipid LNTs consisting of multiple lipid bilayer membranes as a sample-fixation substrate. , Advantages of the discrete LNT over any other tubular nanomaterials can be found in the controllability over the size, dimension, and shape of the nanotube as well as versatile functionalization of surfaces. Using globelike proteins [e.g., ferritin (diameter = 12 nm) and DNA-binding protein from starved cells as a ferritin superfamily (diameter = 9 nm)], they succeeded in the reconstruction of 3-D images of Fe cores from electron energy-loss spectroscopy mapping images or from zero-loss images.…”