β-Lactoglobulin Self-Assembly: Structural Changes in Early Stages and Disulfide Bonding in Fibrils

2013 ◽  
Vol 61 (32) ◽  
pp. 7817-7828 ◽  
Author(s):  
Anant C. Dave ◽  
Simon M. Loveday ◽  
Skelte G. Anema ◽  
Trevor S. Loo ◽  
Gillian E. Norris ◽  
...  
Keyword(s):  
Self Assembly ◽  
Structural Changes ◽  
Disulfide Bonding ◽  
Early Stages ◽  
Β Lactoglobulin

Folding-Controlled Assembly of Ortho-Phenylene-Based Macrocycles

2020 ◽  
Author(s):  
Viraj kirinda ◽  
Scott Hartley
Keyword(s):  
Self Assembly ◽  
Structural Control ◽  
Structural Changes ◽  
Condensation Product ◽  
Gel Permeation Chromatography ◽  
Emergent Behavior ◽  
Order Structure ◽  
High Level ◽  
Alkoxy Groups ◽  
Energy Surfaces

The self-assembly of foldamers into macrocycles is a simple approach to non-biological higher-order structure. Previous work on the co-assembly of ortho-phenylene foldamers with rod-shaped linkers has shown that folding and self-assembly affect each other; that is, the combination leads to new emergent behavior, such as access to otherwise unfavorable folding states. To this point this relationship has been passive. Here, we demonstrate control of self-assembly by manipulating the foldamers’ conformational energy surfaces. A series of o-phenylene decamers and octamers have been assembled into macrocycles using imine condensation. Product distributions were analyzed by gel-permeation chromatography and molecular geometries extracted from a combination of NMR spectroscopy and computational chemistry. The assembly of o-phenylene decamers functionalized with alkoxy groups or hydrogens gives both [2+2] and [3+3] macrocycles. The mixture results from a subtle balance of entropic and enthalpic effects in these systems: the smaller [2+2] macrocycles are entropically favored but require the oligomer to misfold, whereas a perfectly folded decamer fits well within the larger [3+3] macrocycle that is entropically disfavored. Changing the substituents to fluoro groups, however, shifts assembly quantitatively to the [3+3] macrocycle products, even though the structural changes are well-removed from the functional groups directly participating in bond formation. The electron-withdrawing groups favor folding in these systems by strengthening arene–arene stacking interactions, increasing the enthalpic penalty to misfolding. The architectural changes are substantial even though the chemical perturbation is small: analogous o-phenylene octamers do not fit within macrocycles when perfectly folded, and quantitatively misfold to give small macrocycles regardless of substitution. Taken together, these results represent both a high level of structural control in structurally complex foldamer systems and the demonstration of large-amplitude structural changes as a consequence of a small structural effects.

Self-assembly of steps and vacancy lines during the early stages of Ge∕Si(001) heteroepitaxy

2005 ◽  
Vol 87 (25) ◽  
pp. 251908 ◽  
Author(s):  
D. T. Tambe ◽  
C. V. Ciobanu ◽  
V. B. Shenoy
Keyword(s):  
Self Assembly ◽  
Early Stages

scholarly journals Learning from the unexpected in life and DNA self-assembly

2015 ◽  
Vol 11 ◽  
pp. 2713-2720 ◽  
Author(s):  
Jennifer M Heemstra
Keyword(s):  
Research Program ◽  
Self Assembly ◽  
Career Path ◽  
Independent Research ◽  
Unexpected Events ◽  
Early Stages

The greatest lessons in life and science often arise from the unexpected. Thus, rather than viewing these experiences as hindering our progress, they should be embraced and appreciated for their ability to lead to new discoveries. In this perspective, I will discuss the unexpected events that have shaped my career path and the early stages of my independent research program.

Self-assembly of acacia gum and β-lactoglobulin in aqueous dispersion

2007 ◽  
pp. 111-118
Author(s):  
C. Schmitt ◽  
G. Mekhloufi ◽  
J. Hardy ◽  
D. Renard ◽  
P. Robert
Keyword(s):  
Self Assembly ◽  
Aqueous Dispersion ◽  
Acacia Gum ◽  
Β Lactoglobulin

In Situ Monitoring of Structural Changes during Colloidal Self-Assembly

Langmuir ◽  
2006 ◽  
Vol 22 (3) ◽  
pp. 897-900 ◽  
Author(s):  
Yaw Koon Koh ◽  
Chee Cheong Wong
Keyword(s):  
Self Assembly ◽  
Structural Changes ◽  
In Situ Monitoring

Self-Assembly of β-Lactoglobulin and Acacia Gum in Aqueous Solvent:  Structure and Phase-Ordering Kinetics

Langmuir ◽  
2002 ◽  
Vol 18 (26) ◽  
pp. 10323-10333 ◽  
Author(s):  
C. Sanchez ◽  
G. Mekhloufi ◽  
C. Schmitt ◽  
D. Renard ◽  
P. Robert ◽  
...  
Keyword(s):  
Self Assembly ◽  
Solvent Structure ◽  
Ordering Kinetics ◽  
Acacia Gum ◽  
Aqueous Solvent ◽  
Phase Ordering ◽  
Β Lactoglobulin

scholarly journals Nanoscopic Approach to Study the Early Stages of Epithelial to Mesenchymal Transition (EMT) of Human Retinal Pigment Epithelial (RPE) Cells In Vitro

Life ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 128
Author(s):  
Lilia A. Chtcheglova ◽  
Andreas Ohlmann ◽  
Danila Boytsov ◽  
Peter Hinterdorfer ◽  
Siegfried G. Priglinger ◽  
...  
Keyword(s):  
Structural Changes ◽  
Epithelial To Mesenchymal Transition ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Cell Phenotype ◽  
Cytoskeletal Reorganization ◽  
Mesenchymal Transition ◽  
Rpe Cells ◽  
Early Stages

The maintenance of visual function is supported by the proper functioning of the retinal pigment epithelium (RPE), representing a mosaic of polarized cuboidal postmitotic cells. Damage factors such as inflammation, aging, or injury can initiate the migration and proliferation of RPE cells, whereas they undergo a pseudo-metastatic transformation or an epithelial to mesenchymal transition (EMT) from cuboidal epithelioid into fibroblast-like or macrophage-like cells. This process is recognized as a key feature in several severe ocular pathologies, and is mimicked by placing RPE cells in culture, which provides a reasonable and well-characterized in vitro model for a type 2 EMT. The most obvious characteristic of EMT is the cell phenotype switching, accompanied by the cytoskeletal reorganization with changes in size, shape, and geometry. Atomic force microscopy (AFM) has the salient ability to label-free explore these characteristics. Based on our AFM results supported by the genetic analysis of specific RPE differentiation markers, we elucidate a scheme for gradual transformation from the cobblestone to fibroblast-like phenotype. Structural changes in the actin cytoskeletal reorganization at the early stages of EMT lead to the development of characteristic geodomes, a finding that may reflect an increased propensity of RPE cells to undergo further EMT and thus become of diagnostic significance.

scholarly journals Effects of High Intensity Ultrasound on Physiochemical and Structural Properties of Goat Milk β-Lactoglobulin

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3637
Author(s):  
Xinhui Zhou ◽  
Cuina Wang ◽  
Xiaomeng Sun ◽  
Zixuan Zhao ◽  
Mingruo Guo
Keyword(s):  
Thermal Stability ◽  
Structural Properties ◽  
High Intensity ◽  
Structural Changes ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Goat Milk ◽  
High Intensity Ultrasound ◽  
Hydrophobicity Index ◽  
Β Lactoglobulin

This study aimed to compare the effects of high intensity ultrasound (HIU) applied at various amplitudes (20~40%) and for different durations (1~10 min) on the physiochemical and structural properties of goat milk β-lactoglobulin. No significant change was observed in the protein electrophoretic patterns by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Deconvolution and second derivative of the Fourier transform infrared spectra (FTIR) showed that the percentage of β-sheet of goat milk β-lactoglobulin was significantly decreased while those of α-helix and random coils increased after HIU treatment The surface hydrophobicity index and intrinsic fluorescence intensity of samples was enhanced and increased with increasing HIU amplitude or time. Differential scanning calorimetry (DSC) results exhibited that HIU treatments improved the thermal stability of goat milk β-lactoglobulin. Transmission electron microscopy (TEM) of samples showed that the goat milk β-lactoglobulin microstructure had changed and it contained larger aggregates when compared with the untreated goat milk β-lactoglobulin sample. Data suggested that HIU treatments resulted in secondary and tertiary structural changes of goat milk β-lactoglobulin and improved its thermal stability.

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