SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Modesti Mauro) "

Sökning: WFRF:(Modesti Mauro)

  • Resultat 1-8 av 8
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Fornander, Louise, 1984, et al. (författare)
  • Visualizing the Nonhomogeneous Structure of RAD51 Filaments Using Nanofluidic Channels
  • 2016
  • Ingår i: Langmuir. - 0743-7463 .- 1520-5827. ; 32:33, s. 8403-8412
  • Tidskriftsartikel (refereegranskat)abstract
    • RAD51 is the key component of the homologous recombination pathway in eukaryotic cells and performs its task by forming filaments on DNA. In this study we investigate the physical properties of RAD51 filaments formed on DNA using nanofluidic channels and fluorescence microscopy. Contrary to the bacterial ortholog RecA, RAD51 forms inhomogeneous filaments on long DNA in vitro, consisting of several protein patches. We demonstrate that a permanent "kink" in the filament is formed where two patches meet if the stretch of naked DNA between the patches is short. The kinks are readily seen in the present microscopy approach but would be hard to identify using conventional single DNA molecule techniques where the DNA is more stretched. We also demonstrate that protein patches separated by longer stretches of bare DNA roll up on each other and this is visualized as transiently overlapping filaments. RAD51 filaments can be formed at several different conditions, varying the cation (Mg2+ or Ca2+), the DNA substrate (single-stranded or double-stranded), and the RAD51 concentration during filament nucleation, and we compare the properties of the different filaments formed. The results provide important information regarding the physical properties of RAD51 filaments but also demonstrate that nanofluidic channels are perfectly suited to study protein-DNA complexes.
  •  
2.
  • Fritzsche, Joachim, 1977, et al. (författare)
  • A lipid-based passivation scheme for nanofluidics
  • 2012
  • Ingår i: 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012; Okinawa; Japan; 28 October 2012 through 1 November 2012. - : Chemical and Biological Microsystems Society. - 9780979806452 ; , s. 1876-1878
  • Konferensbidrag (refereegranskat)abstract
    • Stretching DNA in nanochannels allows for direct, visual studies of genomic DNA at the single molecule level. In order to facilitate the study of the interaction of linear DNA with proteins in nanochannels, we have implemented a highly effective passivation scheme based on lipid bilayers. We show long-term passivation of nanochannel surfaces to several relevant reagents and demonstrate that the performance of the lipid bilayer is significantly better compared to standard bovine serum albumin-based passivation. Moreover, we demonstrate how the passivated devices allow us to monitor single DNA cleavage events during enzymatic degradation.
  •  
3.
  • Frykholm, Karolin, et al. (författare)
  • Probing Physical Properties of a DNA- Protein Complex Using Nanofluidic Channels
  • 2014
  • Ingår i: Small. - 1613-6810 .- 1613-6829. ; 10:5, s. 884-887
  • Tidskriftsartikel (refereegranskat)abstract
    • A method to investigate physical properties of a DNA-protein complex in solution is demonstrated. By using tapered nanochannels and lipid passivation the persistence length of a RecA filament formed on double-stranded DNA is determined to 1.15 μm, in agreement with the literature, without attaching protein or DNA to any handles or surfaces.
  •  
4.
  • Persson, Fredrik, 1979, et al. (författare)
  • Lipid-Based Passivation in Nanofluidics
  • 2012
  • Ingår i: Nano Letters. - : The American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 12:5, s. 2260-2265
  • Tidskriftsartikel (refereegranskat)abstract
    • Stretching DNA in nanochannels is a useful tool for direct, visual studies of genomic DNA at the single molecule level. To facilitate the study of the interaction of linear DNA with proteins in nanochannels, we have implemented a highly effective passivation scheme based on lipid bilayers. We demonstrate virtually complete long-term passivation of nanochannel surfaces to a range of relevant reagents, including streptavidin-coated quantum dots, RecA proteins, and RecA-DNA complexes. We show that the performance of the lipid bilayer is significantly better than that of standard bovine serum albumin-based passivation. Finally, we show how the passivated devices allow us to monitor single DNA cleavage events during enzymatic degradation by DNase I. We expect that our approach will open up for detailed, systematic studies of a wide range of protein-DNA interactions with high spatial and temporal resolution.
  •  
5.
  •  
6.
  • Fornander, Louise Helena, et al. (författare)
  • Using Nanofluidic Channels to Probe the Dynamics of Rad51-DNA Filaments
  • 2014
  • Ingår i: Biophysical Journal. - 0006-3495 .- 1542-0086. ; 106:2, s. 692A-693A
  • Tidskriftsartikel (övrigt vetenskapligt)abstract
    • Rad51 is a key protein involved in the strand exchange reaction, a reaction where genetic material is transferred between two homologous DNA strands. Strand exchange is initiated by Rad51 forming a helical filament around single-stranded DNA (ssDNA), and the strand exchange is thereafter executed with a homologous double-stranded DNA (dsDNA). The structure of Rad51-DNA filaments, and also the activity of the strand exchange reaction, is dependent on the presence of ATP and dications, where Ca2+ has been shown to promote a higher degree of strand exchange than Mg2+.
  •  
7.
  • Frykholm, Karolin, et al. (författare)
  • Probing Physical Properties of a DNA-Protein Complex Using Nanofluidic Channels
  • 2014
  • Ingår i: Biophysical Journal. - 0006-3495 .- 1542-0086. ; 106:2, s. 428A-429A
  • Tidskriftsartikel (övrigt vetenskapligt)abstract
    • Nanofluidic channels have become an important tool to investigate single DNA molecules both from a fundamental polymer physics perspective as well as in e.g. optical mapping techniques. However, less effort has been made to study DNA-protein complexes. A main reason is that the extreme surface-to-volume ratio in the nanochannels causes most proteins to stick to the channel walls. We have recently overcome this problem by coating the channels with a lipid bilayer, thereby eliminating sticking.
  •  
8.
  • van Mameren, Joost, et al. (författare)
  • Unraveling the structure of DNA during overstretching by using multicolor, single-molecule fluorescence imaging.
  • 2009
  • Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 1091-6490. ; 106:43, s. 18231-6
  • Tidskriftsartikel (refereegranskat)abstract
    • Single-molecule manipulation studies have revealed that double-stranded DNA undergoes a structural transition when subjected to tension. At forces that depend on the attachment geometry of the DNA (65 pN or 110 pN), it elongates approximately 1.7-fold and its elastic properties change dramatically. The nature of this overstretched DNA has been under debate. In one model, the DNA cooperatively unwinds, while base pairing remains intact. In a competing model, the hydrogen bonds between base pairs break and two single DNA strands are formed, comparable to thermal DNA melting. Here, we resolve the structural basis of DNA overstretching using a combination of fluorescence microscopy, optical tweezers, and microfluidics. In DNA molecules undergoing the transition, we visualize double- and single-stranded segments using specific fluorescent labels. Our data directly demonstrate that overstretching comprises a gradual conversion from double-stranded to single-stranded DNA, irrespective of the attachment geometry. We found that these conversions favorably initiate from nicks or free DNA ends. These discontinuities in the phosphodiester backbone serve as energetically favorable nucleation points for melting. When both DNA strands are intact and no nicks or free ends are present, the overstretching force increases from 65 to 110 pN and melting initiates throughout the molecule, comparable to thermal melting. These results provide unique insights in the thermodynamics of DNA and DNA-protein interactions.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-8 av 8

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy