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Structure and Aqueous Phase Behaviour of Fmoc-Diphenylalanine Self-Assembly

Chincoli, Miriana Carmela LU (2023) KEMP30 20231
Department of Chemistry
Abstract
N-(9-fluorenylmethoxycarbonyl)-diphenylalanine (Fmoc-FF) is a combination of two phenylalanine amino acids connected by a peptide bond and protected by a Fmoc group. This dipeptide exhibits unique self-assembly properties, forming a variety of structures such as nanofibers, nanotubes, and hydrogels. The aim of this project is to investigate the structure and phase behaviour of self-assembled Fmoc-FF.
To achieve this goal, two sets of samples were prepared in water at pH 10, the value at which hydrogel formation occurs above a concentration threshold of 0.5wt%. The samples were prepared using two different bases: sodium hydroxide (NaOH) and tetrabutylammonium hydroxide (TBAH). The method employed for sample preparation differs from what... (More)
N-(9-fluorenylmethoxycarbonyl)-diphenylalanine (Fmoc-FF) is a combination of two phenylalanine amino acids connected by a peptide bond and protected by a Fmoc group. This dipeptide exhibits unique self-assembly properties, forming a variety of structures such as nanofibers, nanotubes, and hydrogels. The aim of this project is to investigate the structure and phase behaviour of self-assembled Fmoc-FF.
To achieve this goal, two sets of samples were prepared in water at pH 10, the value at which hydrogel formation occurs above a concentration threshold of 0.5wt%. The samples were prepared using two different bases: sodium hydroxide (NaOH) and tetrabutylammonium hydroxide (TBAH). The method employed for sample preparation differs from what has been reported in literature up to this point.
The samples were examined and analysed using various experimental techniques. The monomer solubility of Fmoc-FF in the two different solutions was determined by Static Light Scattering and it was found that the monomer solubility of one set was four times greater than the other.
Two distinct structures were revealed in the two sets of samples by employing X-Ray Scattering technique. The presence of fibres and ribbons was detected in the NaOH-treated samples, while only fibres were observed in the TBAH-treated samples. These findings were further corroborated by Cryo-Transmission Electron Microscopy, which also unveiled the presence of twisted ribbons and an overlapping mesh of fibres as the concentration of the dipeptide increased. The phase behaviour of the samples was investigated by examining their birefringence at different temperatures using Cross Polarization. Considering the wide application of this dipeptide across various scientific fields, studying its structure and behaviour under different conditions is of great importance and can provide inspiration for future applications. (Less)
Popular Abstract
The main objective of this research project was to investigate the structure and phase behaviour of a self-assembled dipeptide known for its exceptional self-assembly capabilities, enabling the formation of diverse structures such as nanofibers, nanotubes, and hydrogels. Peptides are chain molecules composed of amino acids just as proteins, but generally shorter. In this case only two amino acids.
Two sets of samples were prepared using different bases, sodium hydroxide (NaOH) and tetrabutylammonium hydroxide (TBAH), in water at a pH of 10, revealing interesting insights. It was discovered that the samples treated with NaOH showed four times higher monomer solubility of the dipeptide compared to the samples treated with TBAH. Further... (More)
The main objective of this research project was to investigate the structure and phase behaviour of a self-assembled dipeptide known for its exceptional self-assembly capabilities, enabling the formation of diverse structures such as nanofibers, nanotubes, and hydrogels. Peptides are chain molecules composed of amino acids just as proteins, but generally shorter. In this case only two amino acids.
Two sets of samples were prepared using different bases, sodium hydroxide (NaOH) and tetrabutylammonium hydroxide (TBAH), in water at a pH of 10, revealing interesting insights. It was discovered that the samples treated with NaOH showed four times higher monomer solubility of the dipeptide compared to the samples treated with TBAH. Further investigation revealed distinct structures in the two set of sample. The NaOH-treated samples exhibited long fibers, with radius of 3 nm coexisting with ribbons having a radius of 12 nm and axial ratio about 3. The TBAH-treated samples exclusively showed long fibers with radius of 1.9 nm. Microscopic imaging techniques confirmed the presence of twisted ribbons and overlapping mesh-like structures of fibers, particularly at higher concentrations of the dipeptide. The fibers and ribbons form a transient network so that the samples form hydrogels.
This study introduced a new method for preparing Fmoc-FF fibers and hydrogels, shedding new light on the structural aspects and properties of this self-assembling dipeptide. By advancing our understanding of Fmoc-FF's behaviour under different conditions, these findings hold significant potential for diverse applications in various scientific disciplines. (Less)
Please use this url to cite or link to this publication:
author
Chincoli, Miriana Carmela LU
supervisor
organization
course
KEMP30 20231
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Aqueous Phase Behaviour, Fmoc-FF, Peptide Structure, Self-Assembly, Physical Chemistry
language
English
id
9119597
date added to LUP
2023-06-14 09:47:51
date last changed
2023-06-14 09:47:51
@misc{9119597,
  abstract     = {{N-(9-fluorenylmethoxycarbonyl)-diphenylalanine (Fmoc-FF) is a combination of two phenylalanine amino acids connected by a peptide bond and protected by a Fmoc group. This dipeptide exhibits unique self-assembly properties, forming a variety of structures such as nanofibers, nanotubes, and hydrogels. The aim of this project is to investigate the structure and phase behaviour of self-assembled Fmoc-FF.
To achieve this goal, two sets of samples were prepared in water at pH 10, the value at which hydrogel formation occurs above a concentration threshold of 0.5wt%. The samples were prepared using two different bases: sodium hydroxide (NaOH) and tetrabutylammonium hydroxide (TBAH). The method employed for sample preparation differs from what has been reported in literature up to this point.
The samples were examined and analysed using various experimental techniques. The monomer solubility of Fmoc-FF in the two different solutions was determined by Static Light Scattering and it was found that the monomer solubility of one set was four times greater than the other.
Two distinct structures were revealed in the two sets of samples by employing X-Ray Scattering technique. The presence of fibres and ribbons was detected in the NaOH-treated samples, while only fibres were observed in the TBAH-treated samples. These findings were further corroborated by Cryo-Transmission Electron Microscopy, which also unveiled the presence of twisted ribbons and an overlapping mesh of fibres as the concentration of the dipeptide increased. The phase behaviour of the samples was investigated by examining their birefringence at different temperatures using Cross Polarization. Considering the wide application of this dipeptide across various scientific fields, studying its structure and behaviour under different conditions is of great importance and can provide inspiration for future applications.}},
  author       = {{Chincoli, Miriana Carmela}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Structure and Aqueous Phase Behaviour of Fmoc-Diphenylalanine Self-Assembly}},
  year         = {{2023}},
}