scholarly journals Application of SNAP-Tag in Expansion Super-Resolution Microscopy Using DNA Oligostrands

2021 ◽  
Vol 9 ◽  
Author(s):  
Longfang Yao ◽  
Li Zhang ◽  
Yiyan Fei ◽  
Liwen Chen ◽  
Lan Mi ◽  
...  

Expansion super-resolution technology is a new technology developed in recent years. It anchors the dye on the hydrogel and the dye expands with the expansion of the hydrogel so that a super-resolution map can be obtained under an ordinary microscope. However, by labeling the target protein with a first antibody and secondary antibody, the distance between the fluorescent group and the actual target protein is greatly increased. Although fluorescent proteins can also be used for expansion super-resolution to reduce this effect, the fluorescent protein is often destroyed during sample preparation. To solve this problem, we developed a novel label system for expansion microscopy, based on a DNA oligostrand linked with a fluorescent dye, acrylamide group (linker), and benzoylguanine (BG, a small substrate molecule for SNAP-tag). This protocol greatly reduced the error between the position of fluorescent group and the actual target protein, and also reduced loss of the fluorescent group during sample preparation.

2019 ◽  
Author(s):  
Jeffrey Chang ◽  
Matthew Romei ◽  
Steven Boxer

<p>Double-bond photoisomerization in molecules such as the green fluorescent protein (GFP) chromophore can occur either via a volume-demanding one-bond-flip pathway or via a volume-conserving hula-twist pathway. Understanding the factors that determine the pathway of photoisomerization would inform the rational design of photoswitchable GFPs as improved tools for super-resolution microscopy. In this communication, we reveal the photoisomerization pathway of a photoswitchable GFP, rsEGFP2, by solving crystal structures of <i>cis</i> and <i>trans</i> rsEGFP2 containing a monochlorinated chromophore. The position of the chlorine substituent in the <i>trans</i> state breaks the symmetry of the phenolate ring of the chromophore and allows us to distinguish the two pathways. Surprisingly, we find that the pathway depends on the arrangement of protein monomers within the crystal lattice: in a looser packing, the one-bond-flip occurs, whereas in a tighter packing (7% smaller unit cell size), the hula-twist occurs.</p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p> <p> </p>


ACS Nano ◽  
2015 ◽  
Vol 9 (10) ◽  
pp. 9528-9541 ◽  
Author(s):  
Sam Duwé ◽  
Elke De Zitter ◽  
Vincent Gielen ◽  
Benjamien Moeyaert ◽  
Wim Vandenberg ◽  
...  

2019 ◽  
Author(s):  
Jeffrey Chang ◽  
Matthew Romei ◽  
Steven Boxer

<p>Double-bond photoisomerization in molecules such as the green fluorescent protein (GFP) chromophore can occur either via a volume-demanding one-bond-flip pathway or via a volume-conserving hula-twist pathway. Understanding the factors that determine the pathway of photoisomerization would inform the rational design of photoswitchable GFPs as improved tools for super-resolution microscopy. In this communication, we reveal the photoisomerization pathway of a photoswitchable GFP, rsEGFP2, by solving crystal structures of <i>cis</i> and <i>trans</i> rsEGFP2 containing a monochlorinated chromophore. The position of the chlorine substituent in the <i>trans</i> state breaks the symmetry of the phenolate ring of the chromophore and allows us to distinguish the two pathways. Surprisingly, we find that the pathway depends on the arrangement of protein monomers within the crystal lattice: in a looser packing, the one-bond-flip occurs, whereas in a tighter packing (7% smaller unit cell size), the hula-twist occurs.</p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p> <p> </p>


2021 ◽  
pp. mbc.E21-01-0044
Author(s):  
Mitsuo Osuga ◽  
Tamako Nishimura ◽  
Shiro Suetsugu

Super-resolution microscopy determines the localization of fluorescent proteins with high precision, beyond the diffraction limit of light. Super-resolution microscopic techniques include photoactivated localization microscopy (PALM), which can localize a single protein by the stochastic activation of its fluorescence. In the determination of single-molecule localization by PALM, the number of molecules that can be analyzed per image is limited. Thus, many images are required to reconstruct the localization of numerous molecules in the cell. However, most fluorescent proteins lose their fluorescence upon fixation. Here, we combined the amino acid substitutions of two Eos protein derivatives, Skylan-S and mEos4b, which are a green reversibly photoswitchable fluorescent protein (RSFP) and a fixation-resistant green-to-red photo-convertible fluorescent protein, respectively, resulting in the fixation-resistant Skylan-S (frSkylan-S), a green RSFP. The frSkylan-S protein is inactivated by excitation light and re-activated by irradiation with violet light, and retained more fluorescence after aldehyde fixation than Skylan-S. The qualities of the frSkylan-S fusion proteins were sufficiently high in PALM observations, as examined using α-tubulin and clathrin light chain. Furthermore, frSkylan-S can be combined with antibody staining for multicolor imaging. Therefore, frSkylan-S is a green fluorescent protein suitable for PALM imaging under aldehyde-fixation conditions.


2017 ◽  
Vol 37 (3) ◽  
pp. 0318008
Author(s):  
彭鼎铭 Peng Dingming ◽  
付志飞 Fu Zhifei ◽  
徐平勇 Xu Pingyong

Author(s):  
Monika Pawlowska ◽  
Ron Tenne ◽  
Bohnishikha Ghosh ◽  
Adrian Makowski ◽  
Radek Lapkiewicz

Abstract Super-resolution microscopy techniques have pushed the limits of resolution in optical imaging by more than an order of magnitude. However, these methods often require long acquisition times as well as complex setups and sample preparation protocols. Super-resolution Optical Fluctuation Imaging (SOFI) emerged over ten years ago as an approach that exploits temporal and spatial correlations within the acquired images to obtain increased resolution with less strict requirements. This review follows the progress of SOFI from its first demonstration to the development of a branch of methods that treat fluctuations as a source of contrast, rather than noise. Among others, we highlight the implementation of SOFI with standard fluorescent proteins as well as the microscope modification that facilitate 3D imaging and the application of modern cameras. Going beyond the classical framework of SOFI, we explore different innovative concepts from deep neural networks all the way to a quantum analogue of SOFI, antibunching microscopy. While SOFI has not reached the same level of ubiquity as other super-resolution methods, our overview finds significant progress and substantial potential for the concept of leveraging fluorescence fluctuations to obtain super-resolved images.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiwoong Kwon ◽  
Jong-Seok Park ◽  
Minsu Kang ◽  
Soobin Choi ◽  
Jumi Park ◽  
...  

2015 ◽  
Vol 51 (70) ◽  
pp. 13451-13453 ◽  
Author(s):  
Wei Qiang Ong ◽  
Y. Rose Citron ◽  
Joerg Schnitzbauer ◽  
Daichi Kamiyama ◽  
Bo Huang

D2O improves the photon yield of photoactivatable fluorescent proteins and thus the localization precision for super-resolution microscopy.


ChemPhysChem ◽  
2014 ◽  
Vol 15 (4) ◽  
pp. 756-762 ◽  
Author(s):  
Nickels A. Jensen ◽  
Johann G. Danzl ◽  
Katrin I. Willig ◽  
Flavie Lavoie-Cardinal ◽  
Tanja Brakemann ◽  
...  

Science ◽  
2020 ◽  
Vol 367 (6473) ◽  
pp. 76-79 ◽  
Author(s):  
Matthew G. Romei ◽  
Chi-Yun Lin ◽  
Irimpan I. Mathews ◽  
Steven G. Boxer

Rotation around a specific bond after photoexcitation is central to vision and emerging opportunities in optogenetics, super-resolution microscopy, and photoactive molecular devices. Competing roles for steric and electrostatic effects that govern bond-specific photoisomerization have been widely discussed, the latter originating from chromophore charge transfer upon excitation. We systematically altered the electrostatic properties of the green fluorescent protein chromophore in a photoswitchable variant, Dronpa2, using amber suppression to introduce electron-donating and electron-withdrawing groups to the phenolate ring. Through analysis of the absorption (color), fluorescence quantum yield, and energy barriers to ground- and excited-state isomerization, we evaluate the contributions of sterics and electrostatics quantitatively and demonstrate how electrostatic effects bias the pathway of chromophore photoisomerization, leading to a generalized framework to guide protein design.


Sign in / Sign up

Export Citation Format

Share Document