The Formation and Self-Assembly of Long Prebiotic Oligomers Produced by the Condensation of Unactivated Amino Acids on Oxide Surfaces

We report for the very first time self-assembly of Cysteine and Methionine to discrenible strucutres under neutral condition. To get insights into the structure formation, thioflavin T and Congo red binding assays were done which revealed that aggregates may not have amyloid like characteristics. The nature of interactions which lead to such self-assemblies was purported by coincubating assemblies in urea and mercaptoethanol. Further interaction of aggregates with short amyloidogenic dipeptide diphenylalanine (FF) was assessed. While cysteine aggregates completely disrupted FF fibres, methionine albeit triggered fibrillation. The cytotoxicity assays of cysteine and methionine structures were performed on Human Neuroblastoma IMR-32 cells which suggested that aggregates are not cytotoxic in nature and thus, may not have amyloid like etiology. The results presented in the manuscript are striking, since to the best of our knowledge,this is the first report which demonstrates that even non-aromatic amino acids (cysteine and methionine) can undergo spontaneous self-assembly to form ordered aggregates.

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Directive Effect of Chain Length in Modulating Peptide Nano-assemblies

Protein and Peptide Letters ◽

10.2174/0929866527666200224114627 ◽

2020 ◽

Vol 27 (9) ◽

pp. 923-929

Author(s):

Gaurav Pandey ◽

Prem Prakash Das ◽

Vibin Ramakrishnan

Keyword(s):

Electron Microscopy ◽

Amino Acids ◽

Light Scattering ◽

Chain Length ◽

Self Assembly ◽

The Self ◽

Ionic Charge ◽

Self Assembling ◽

Biophysical Techniques

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.

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Noncanonical Amino Acids for Hypoxia-Responsive Peptide Self-Assembly and Fluorescence

Journal of the American Chemical Society ◽

10.1021/jacs.1c06435 ◽

2021 ◽

Author(s):

Binbin Hu ◽

Na Song ◽

Yawei Cao ◽

Mingming Li ◽

Xin Liu ◽

...

Keyword(s):

Amino Acids ◽

Self Assembly ◽

Noncanonical Amino Acids

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Fullerene self-assembly onto (MeO)3Si(CH2)3NH2-modified oxide surfaces

Journal of the American Chemical Society ◽

10.1021/ja00056a080 ◽

1993 ◽

Vol 115 (3) ◽

pp. 1193-1194 ◽

Cited By ~ 143

Author(s):

Kaimin Chen ◽

W. Brett Caldwell ◽

Chad A. Mirkin

Keyword(s):

Self Assembly ◽

Oxide Surfaces

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Self-Assembly of Alkanethiol Molecules onto Platinum and Platinum Oxide Surfaces

Langmuir ◽

10.1021/la034245b ◽

2003 ◽

Vol 19 (17) ◽

pp. 6744-6749 ◽

Cited By ~ 90

Author(s):

Zhiyong Li ◽

Shun-Chi Chang ◽

R. Stanley Williams

Keyword(s):

Self Assembly ◽

Platinum Oxide ◽

Oxide Surfaces

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Self-assembly of aromatic amino acids: a molecular dynamics study

Physical Chemistry Chemical Physics ◽

10.1039/c8cp06239k ◽

2018 ◽

Vol 20 (48) ◽

pp. 30525-30536 ◽

Cited By ~ 10

Author(s):

Sahin Uyaver ◽

Helen W. Hernandez ◽

M. Gokhan Habiboglu

Keyword(s):

Molecular Dynamics ◽

Amino Acids ◽

Self Assembly ◽

Aromatic Amino Acids

Common structures identified in the assembly of aromatic amino acids and their mixtures include the four-fold tube (a and b) and the zig-zag structure (c and d).

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Unusual Aggregation Properties of Single Amino Acid L-Lysine Hydrochloride

10.26434/chemrxiv.14152976 ◽

2021 ◽

Author(s):

Bharti Koshti ◽

Ramesh Singh ◽

Vivekshinh Kshtriya ◽

Shanka Walia ◽

Dhiraj Bhatia ◽

...

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Self Assembly ◽

Short Term Memory ◽

Deionized Water ◽

The Body ◽

The Self ◽

Single Amino Acid ◽

Maple Syrup ◽

Self Assembling

. The self-assembly of single amino acids is very important topic of research since there are plethora of diseases like phenylketonuria, tyrosinemia, hypertryptophanemia, hyperglycinemia, cystinuria and maple syrup urine disease to name a few which are caused by the accumulation or excess of amino acids. These are in-born errors of metabolisms (IEM’s) which are caused due to the deficiency of enzymes involved in catabolic pathways of these enzymes. Hence, it is very pertinent to understand the fate of these excess amino acids in the body and their self-assembling behaviour at molecular level. From the previous literature reports it may be surmised that the single amino acids like Phenylalanine, Tyrosine, Tryptophan, Cysteine and Methionine assemble to amyloid like structures, and hence have important implications in the pathophysiology of IEM’s like phenylketonuria, tyrosinemia, hypertryptophanemia, cystinuria and hypermethioninemia respectively. In this manuscript we report the self-assembly of lysine hydrocholride to fiber like structures in deionized water. It could be observed that lysine assemble to globular structures in fresh condition and then gradually changes to fiber like morphologies by self-association over time after 24 hours. These fibers gradually change to tubular morphologies after 3 day followed by fractal irregular morphologies in 10 and 15 days respectively. Notably, lysine exists as positively charged amino acid at physiological pH and the amine groups in lysine remain protonated. Hence, the self-assembling properties of lysine hydrochloride in deionized water is also pertinent and give insights into the fate of this amino acid in body in case it remains unmetabolized. Further, MTT assays were done to analyse the toxicities of these aggregates and the assay suggest their cytotoxic nature on SHSY5Y neural cell lines. Hence, the aggregation of lysine may be attributed to the pathological symptoms caused in diseases like hyperlysinemia which is associated with the neurological problems like seizures and short-term memory as observed in case of amyloid diseases like Parkinson’s and Alzheimer’s to name a few.

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