Role of Molecular Interaction in Anisotropic Light Scattering by Liquids

1967 ◽  
Vol 46 (10) ◽  
pp. 4090-4099 ◽  
Author(s):  
Stanisℏaw Kielich
2020 ◽  
Vol 27 (9) ◽  
pp. 923-929
Author(s):  
Gaurav Pandey ◽  
Prem Prakash Das ◽  
Vibin Ramakrishnan

Background: RADA-4 (Ac-RADARADARADARADA-NH2) is the most extensively studied and marketed self-assembling peptide, forming hydrogel, used to create defined threedimensional microenvironments for cell culture applications. Objectives: In this work, we use various biophysical techniques to investigate the length dependency of RADA aggregation and assembly. Methods: We synthesized a series of RADA-N peptides, N ranging from 1 to 4, resulting in four peptides having 4, 8, 12, and 16 amino acids in their sequence. Through a combination of various biophysical methods including thioflavin T fluorescence assay, static right angle light scattering assay, Dynamic Light Scattering (DLS), electron microscopy, CD, and IR spectroscopy, we have examined the role of chain-length on the self-assembly of RADA peptide. Results: Our observations show that the aggregation of ionic, charge-complementary RADA motifcontaining peptides is length-dependent, with N less than 3 are not forming spontaneous selfassemblies. Conclusion: The six biophysical experiments discussed in this paper validate the significance of chain-length on the epitaxial growth of RADA peptide self-assembly.


ChemBioChem ◽  
2021 ◽  
Author(s):  
Santiago A Gomez ◽  
Natalia Rojas-Valencia ◽  
Sara Gomez ◽  
Chiara Cappelli ◽  
Albeiro Restrepo

2012 ◽  
Vol 2 (1) ◽  
pp. 021801 ◽  
Author(s):  
Nazila Soleimani ◽  
Sebastian Knabe ◽  
Gottfried H. Bauer ◽  
Tom Markvart ◽  
Otto L. Muskens

1992 ◽  
Vol 271 ◽  
Author(s):  
I. Laaziz ◽  
A. Larbot ◽  
C. Guizard ◽  
A. Julbe ◽  
L. Cot

ABSTRACTZirconium propoxide hydrolysis was performed with the help of an esterification reaction using acetic acid. Products, obtained according to the value of hydrolysis ratio, are successively crystals, sols and gels or precipitates. The similarity of FUR and NMR spectra for crystals and gels allows to think that the arrangements of ligands around the zirconium atoms are close. The crystalline structure determination permits to precise the environment : acetate groups are always bridging and propoxy groups can be bridging or terminal. Clusters containing 9 zirconium atoms, bridged by oxygen atoms, exist in the structure. The colloid size growth was performed by light scattering. A discussion of the role of acetic acid and the competition between the possible reactions is given.


CrystEngComm ◽  
2016 ◽  
Vol 18 (1) ◽  
pp. 149-156 ◽  
Author(s):  
Sucheta Sengupta ◽  
Maayan Perez ◽  
Alexander Rabkin ◽  
Yuval Golan

We report the formation of size tunable PbS nanocubes induced by the presence of trisodium citrate during growth of PbS thin films by chemical bath deposition. The presence of citrate induces growth by the cluster mechanism which is monitored by XRD and HRSEM, along with real time light scattering and optical absorption measurements.


2004 ◽  
Vol 36 (9) ◽  
pp. 583-588 ◽  
Author(s):  
Hong-Qiang Cheng ◽  
Gen-Jun Xu

Abstract Human group IB phospholipase A2 (IB-PLA2) and its zymogen (proIB-PLA2) were purified from E. coli. Refolding was carried out by diluting the denatured forms of both IB-PLA2 and proIB-PLA2 with renaturation buffer in which the disulfide bonds were completely reduced. The refolding yield of proIB-PLA2 was increased by about 50% over that of the mature enzyme. The refolding of IB-PLA2 usually produced aggregates under normal conditions, as determined by light scattering. In addition, the unfolding experiments showed that the mature enzyme was more stable than the proenzyme toward denaturants in the presence of DTT. Results suggested that the N-terminal sequence rather than its conformation of human proIB-PLA2 played an important role in the refolding process.


Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1046 ◽  
Author(s):  
Božič ◽  
Sitar ◽  
Junkar ◽  
Štukelj ◽  
Pajnič ◽  
...  

Extracellular vesicles (EVs) isolated from biological samples are a promising material for use in medicine and technology. However, the assessment methods that would yield repeatable concentrations, sizes and compositions of the harvested material are missing. A plausible model for the description of EV isolates has not been developed. Furthermore, the identity and genesis of EVs are still obscure and the relevant parameters have not yet been identified. The purpose of this work is to better understand the mechanisms taking place during harvesting of EVs, in particular the role of viscosity of EV suspension. The EVs were harvested from blood plasma by repeated centrifugation and washing of samples. Their size and shape were assessed by using a combination of static and dynamic light scattering. The average shape parameter of the assessed particles was found to be ρ ~ 1 (0.94–1.1 in exosome standards and 0.7–1.2 in blood plasma and EV isolates), pertaining to spherical shells (spherical vesicles). This study has estimated the value of the viscosity coefficient of the medium in blood plasma to be 1.2 mPa/s. It can be concluded that light scattering could be a plausible method for the assessment of EVs upon considering that EVs are a dynamic material with a transient identity.


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