scholarly journals Tuning SAS-6 architecture with monobodies impairs distinct steps of centriole assembly

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Georgios N. Hatzopoulos ◽  
Tim Kükenshöner ◽  
Niccolò Banterle ◽  
Tatiana Favez ◽  
Isabelle Flückiger ◽  
...  
Keyword(s):  
Self Assembly ◽  
Protein Complexes ◽  
Force Microscopy ◽  
Target Interaction ◽  
X Ray Crystallography ◽  
Ring Assembly ◽  
Atomic Force ◽  
Evolutionarily Conserved ◽  
Ring Polymers ◽  
Centriole Assembly

AbstractCentrioles are evolutionarily conserved multi-protein organelles essential for forming cilia and centrosomes. Centriole biogenesis begins with self-assembly of SAS-6 proteins into 9-fold symmetrical ring polymers, which then stack into a cartwheel that scaffolds organelle formation. The importance of this architecture has been difficult to decipher notably because of the lack of precise tools to modulate the underlying assembly reaction. Here, we developed monobodies against Chlamydomonas reinhardtii SAS-6, characterizing three in detail with X-ray crystallography, atomic force microscopy and cryo-electron microscopy. This revealed distinct monobody-target interaction modes, as well as specific consequences on ring assembly and stacking. Of particular interest, monobody MBCRS6-15 induces a conformational change in CrSAS-6, resulting in the formation of a helix instead of a ring. Furthermore, we show that this alteration impairs centriole biogenesis in human cells. Overall, our findings identify monobodies as powerful molecular levers to alter the architecture of multi-protein complexes and tune centriole assembly.

scholarly journals Deposition of exchange-coupled dinickel complexes on gold substrates utilizing ambidentate mercapto-carboxylato ligands

2017 ◽  
Vol 8 ◽  
pp. 1375-1387 ◽  
Author(s):  
Martin Börner ◽  
Laura Blömer ◽  
Marcus Kischel ◽  
Peter Richter ◽  
Georgeta Salvan ◽  
...  
Keyword(s):  
Self Assembly ◽  
Density Functional ◽  
Ionization Mass ◽  
Temperature Dependent ◽  
Force Microscopy ◽  
X Ray Crystallography ◽  
Planar Surfaces ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Gold Substrates

The chemisorption of magnetically bistable transition metal complexes on planar surfaces has recently attracted increased scientific interest due to its potential application in various fields, including molecular spintronics. In this work, the synthesis of mixed-ligand complexes of the type [NiII 2L(L’)](ClO4), where L represents a 24-membered macrocyclic hexaazadithiophenolate ligand and L’ is a ω-mercapto-carboxylato ligand (L’ = HS(CH2)5CO2 − (6), HS(CH2)10CO2 − (7), or HS(C6H4)2CO2 − (8)), and their ability to adsorb on gold surfaces is reported. Besides elemental analysis, IR spectroscopy, electrospray ionization mass spectrometry (ESIMS), UV–vis spectroscopy, and X-ray crystallography (for 6 and 7), the compounds were also studied by temperature-dependent magnetic susceptibility measurements (for 7 and 8) and (broken symmetry) density functional theory (DFT) calculations. An S = 2 ground state is demonstrated by temperature-dependent susceptibility and magnetization measurements, achieved by ferromagnetic coupling between the spins of the Ni(II) ions in 7 (J = +22.3 cm−1) and 8 (J = +20.8 cm−1; H = −2JS1S2). The reactivity of complexes 6–8 is reminiscent of that of pure thiolato ligands, which readily chemisorb on Au surfaces as verified by contact angle, atomic force microscopy (AFM) and spectroscopic ellipsometry measurements. The large [Ni2L] tail groups, however, prevent the packing and self-assembly of the hydrocarbon chains. The smaller film thickness of 7 is attributed to the specific coordination mode of the coligand. Results of preliminary transport measurements utilizing rolled-up devices are also reported.

Clathrin-Inspired Coating and Stabilization of Liposomes by DNA Self-Assembly

2019 ◽  
Author(s):  
Kevin N. Baumann ◽  
Luca Piantanida ◽  
Javier García-Nafría ◽  
Diana Sobota ◽  
Kislon Voïtchovsky ◽  
...  
Keyword(s):  
Self Assembly ◽  
Mechanical Stability ◽  
Lipid Vesicles ◽  
The Self ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cryo Electron Microscopy ◽  
Further Development ◽  
Liposome Surface ◽  
Dna Coating

The self-assembly of the protein clathrin on biological membranes facilitates essential processes of endocytosis in biological systems and has provided a source of inspiration for materials design by the highly ordered structural appearance. By mimicking the architecture of clathrin self-assemblies to coat liposomes with biomaterials, new classes of hybrid carriers can be derived. Here we present a method for fabricating DNA-coated liposomes by hydrophobically anchoring and subsequently growing a DNA network on the liposome surface which structurally mimics clathrin assemblies. Dynamic light scattering (DLS), ζ-potential and cryo-electron microscopy (cryo-EM) measurements independently demonstrate successful DNA coating. Nanomechanical measurements conducted with atomic force microscopy (AFM) show that the DNA coating enhances the mechanical stability of the liposomes relative to uncoated ones. Furthermore, we provide the possibility to reverse the coating process by triggering the disassembly of the DNA coating through a toehold-mediated displacement reaction. Our results describe a straightforward, versatile, and reversible approach for coating and stabilizing lipid vesicles by an interlaced DNA network. This method has potential for further development towards the ordered arrangement of tailored functionalities on the surfaces of liposomes and for applications as hybrid nanocarrier.

scholarly journals Morphometric characterization of fibrinogen's αC regions and their role in fibrin self-assembly and molecular organization

Nanoscale ◽  
2017 ◽  
Vol 9 (36) ◽  
pp. 13707-13716 ◽  
Author(s):  
Anna D. Protopopova ◽  
Rustem I. Litvinov ◽  
Dennis K. Galanakis ◽  
Chandrasekaran Nagaswami ◽  
Nikolay A. Barinov ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
Molecular Organization ◽  
Microscopy Imaging ◽  
Force Microscopy ◽  
Atomic Force ◽  
Atomic Force Microscopy Imaging ◽  
Morphometric Characterization

High-resolution atomic force microscopy imaging reveals the role of fibrinogen αC regions in the early stages of fibrin self-assembly.

Self-assembly layer-by-layer fabrication using porphyrin dye anion and polycation

2009 ◽  
Vol 13 (07) ◽  
pp. 774-778 ◽  
Author(s):  
Byung-Soon Kim ◽  
Young-A Son
Keyword(s):  
Ultrathin Films ◽  
Self Assembly ◽  
Film Surface ◽  
Layer By Layer ◽  
Preparation Technique ◽  
Force Microscopy ◽  
Atomic Force ◽  
Diallyldimethylammonium Chloride ◽  
Afm Analysis ◽  
Progressive Growth

In this study, self-assembled alternating film using poly(diallyldimethylammonium chloride) (PDDAC) and meso-tetrakis(4-carboxyphenyl)porphyrin (MTCP) was prepared as a multilayer deposition on glass substrate. This preparation technique for dye deposition may provide new feasibilities to achieve the manufacture of ultrathin films for nanotechnology application. The deposition films were characterized by UV-vis spectrophotometer and Atomic Force Microscopy (AFM) analysis. The results of UV-vis spectra showed that the absorbance characteristic of the multilayer films linearly increased with an increased number of PDDAC and MTCP bilayers. AFM analysis showed the film surface was relatively uniform and the progressive growth of layers was determined.

scholarly journals Visualization and identification of hepatitis c viral particles by atomic force microscopy combined with ms/ms analysis

2010 ◽  
Vol 56 (1) ◽  
pp. 26-39 ◽  
Author(s):  
A.L. Kaysheva ◽  
Yu.D. Ivanov ◽  
V.G. Zgoda ◽  
P.A. Frantsuzov ◽  
T.O. Pleshakova ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Hepatitis C ◽  
Protein Complexes ◽  
Mass Spectrometric ◽  
Force Microscopy ◽  
Atomic Force ◽  
Spectrometric Identification ◽  
Detection And Identification ◽  
Viral Particles ◽  
Mass Spectrometric Identification

Possibility of detection and identification of hepatitis C viral particles with mass spectrometry (MS) in combination with atomic force microscopy (AFM) had been investigated. AFM/MS approach is based on two technologies: 1. AFM-biospecific fishing that allows to detect, concentrate from solution and to count protein complexes on a surface of AFM-nanochip; 2. mass spectrometric identification of these complexes. AFM-biospecific fishing of HCVcoreAg from solution was carried onto surface of AFM-nanochips with immobilized anti-HCVcoreAg. It was shown that HCVcoreAg/anti-HCVcoreim complexes were formed onto AFM-nanochips in quantity sufficient for mass spectrometric identification. Thus, AFM/MS approach allows to identify fragments of hepatitis C virus fished onto a surface of AFM-nanochip from serum.

scholarly journals Electric Field Assisted Self-Assembly of Viruses into Colored Thin Films

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1310 ◽  
Author(s):  
James J. Tronolone ◽  
Michael Orrill ◽  
Wonbin Song ◽  
Hyun Soo Kim ◽  
Byung Yang Lee ◽  
...  
Keyword(s):  
Electric Field ◽  
Self Assembly ◽  
Force Microscopy ◽  
Thin Film Coatings ◽  
Atomic Force ◽  
Three Phase ◽  
Constant Rate ◽  
Alignment Technique ◽  
Manufacturing Techniques ◽  
Blue Line

Filamentous viruses called M13 bacteriophages are promising materials for devices with thin film coatings because phages are functionalizable, and they can self-assemble into smectic helicoidal nanofilament structures. However, the existing “pulling” approach to align the nanofilaments is slow and limits potential commercialization of this technology. This study uses an applied electric field to rapidly align the nanostructures in a fixed droplet. The electric field reduces pinning of the three-phase contact line, allowing it to recede at a constant rate. Atomic force microscopy reveals that the resulting aligned structures resemble those produced via the pulling method. The field-assisted alignment results in concentric color bands quantified with image analysis of red, green, and blue line profiles. The alignment technique shown here could reduce self-assembly time from hours to minutes and lend itself to scalable manufacturing techniques such as inkjet printing.

The Specific Binding between Galactose Group and Ricinus Communis Agglutinin (RCA) Investigated with Microcantilever

2012 ◽  
Vol 531-532 ◽  
pp. 600-604
Author(s):  
Hui Yong Zhang ◽  
Ji Hu ◽  
Hui Min Liu
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
Control Experiment ◽  
Ricinus Communis ◽  
Specific Binding ◽  
Specific Interaction ◽  
Protein Layer ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ricinus Communis Agglutinin

The specific recognization between galactose group and Ricinus Communis Agglutinin (RCA) was investigated by microcantilever. The gold side of the microcantilever was covalently bound with N-galactose, RCA and asialofetuin (ASF) via mixed self assembly monolayer of 11-mercaptoundecanoic acid and 6-mercaptohexanol, respectively. After adding RCA into the flowing cell, the deflection could be observed on the N-galactose or ASF modified microcantilever. Meanwhile, the deflection could also be observed after ASF bound to the RCA modified microcantilever. In order to prove that the deflection is caused by the specific interaction between the galactose group and RCA, bovine serum albumin (BSA) was introduced into the flowing cell as control experiment and no obvious deflection was observed. The specific interaction was also confirmed by the evidence that the bound protein layer can be mechanically removed with atomic force microscopy nanolithography technology.

Sign in / Sign up

Export Citation Format

Share Document