Cluster-Based Self-Assembly: Reversible Formation of Polyoxometalate Nanocones and Nanotubes

2009 ◽  
Vol 21 (16) ◽  
pp. 3745-3751 ◽  
Author(s):  
Amjad Nisar ◽  
Jing Zhuang ◽  
Xun Wang
Keyword(s):  
Self Assembly ◽  
Reversible Formation

Self-Assembly of Gold(I) Rings and Reversible Formation of Organometallic [2]Catenanes

2002 ◽  
Vol 8 (3) ◽  
pp. 723-734 ◽  
Author(s):  
Christopher P. McArdle ◽  
Michael J. Irwin ◽  
Michael C. Jennings ◽  
Jagadese J. Vittal ◽  
Richard J. Puddephatt
Keyword(s):  
Self Assembly ◽  
Reversible Formation

scholarly journals Correction to Cluster-Based Self-Assembly: Reversible Formation of Polyoxometalate Nanocones and Nanotubes

2009 ◽  
Vol 21 (19) ◽  
pp. 4746-4746
Author(s):  
Amjad Nisar ◽  
Jing Zhuang ◽  
Xun Wang
Keyword(s):  
Self Assembly ◽  
Reversible Formation

Dynamic boronic acid-mediated autoligation of DNA strands

2012 ◽  
Vol 84 (7) ◽  
pp. 1659-1667 ◽  
Author(s):  
Michael Smietana ◽  
Anthony R. Martin ◽  
Jean-Jacques Vasseur
Keyword(s):  
Nucleic Acid ◽  
Self Assembly ◽  
Boronic Acid ◽  
Dynamic Equilibrium ◽  
Stimuli Responsive ◽  
Structural Units ◽  
Dna Strands ◽  
Dynamic Assembly ◽  
Equilibrium Process ◽  
Reversible Formation

The single common feature of all biological systems is the dependence on self-assembly of molecular units to be morphed into well-defined functional architectures. Thanks to a dynamic equilibrium process, incorrect structural units are rejected with high levels of fidelity. The development of synthetic systems displaying similar attributes is an emerging field with wide applications from biotechnology to medicine. In this context, we developed a stimuli-responsive nucleic acid-based system relying on the reversible formation of cyclic boronate internucleosidic linkages. The dynamic assembly of this new borono-based helix has been accomplished through a DNA- and an RNA-templated autoligation process featuring a 5'-ended boronic acid oligonucleotide connecting to a 3'-ended ribonucleosidic oligonucleotide partner.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

The Nature of Rapidly Extracted Phycocyanin from the Blue-Green Alga Plectonema Boryanum

1971 ◽  
Vol 29 ◽  
pp. 366-367
Author(s):  
M. Kessel ◽  
R. MacColl
Keyword(s):  
Self Assembly ◽  
Analytical Ultracentrifugation ◽  
Uranyl Acetate ◽  
The Self ◽  
Major Protein ◽  
Subunit Structure ◽  
Blue Green Alga ◽  
Thin Sections ◽  
Blue Green Algae ◽  
Cacodylate Buffer

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.

Video real-time imaging of artificial membranes during freeze-drying by cryo-electron microscopy

1988 ◽  
Vol 46 ◽  
pp. 16-17
Author(s):  
Alan S. Rudolph ◽  
Ronald R. Price
Keyword(s):  
Real Time ◽  
Self Assembly ◽  
Freeze Drying ◽  
Video Capture ◽  
Drying Process ◽  
Artificial Membranes ◽  
The Past ◽  
Cryo Electron Microscopy ◽  
Spherical Structures ◽  
Capture Techniques

We have employed cryoelectron microscopy to visualize events that occur during the freeze-drying of artificial membranes by employing real time video capture techniques. Artificial membranes or liposomes which are spherical structures within internal aqueous space are stabilized by water which provides the driving force for spontaneous self-assembly of these structures. Previous assays of damage to these structures which are induced by freeze drying reveal that the two principal deleterious events that occur are 1) fusion of liposomes and 2) leakage of contents trapped within the liposome [1]. In the past the only way to access these events was to examine the liposomes following the dehydration event. This technique allows the event to be monitored in real time as the liposomes destabilize and as water is sublimed at cryo temperatures in the vacuum of the microscope. The method by which liposomes are compromised by freeze-drying are largely unknown. This technique has shown that cryo-protectants such as glycerol and carbohydrates are able to maintain liposomal structure throughout the drying process.

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