Monitoring the Early Stage Self-Assembly of Enzyme-Assisted Peptide Hydrogels

2013 ◽  
Vol 66 (5) ◽  
pp. 572 ◽  
Author(s):  
Richard J. Williams ◽  
James Gardiner ◽  
Anders B. Sorensen ◽  
Silvia Marchesan ◽  
Roger J. Mulder ◽  
...  

The early stages of the self-assembly of peptide hydrogels largely determine their final material properties. Here we discuss experimental methodologies for monitoring the self-assembly kinetics which underpin peptide hydrogel formation. The early stage assembly of an enzyme-catalysed Fmoc-trileucine based self-assembled hydrogel was examined using spectroscopic techniques (circular dichroism, CD, and solution NMR) as well as chromatographic (HPLC) and mechanical (rheology) techniques. Optimal conditions for enzyme-assisted hydrogel formation were identified and the kinetics examined. A lag time associated with the formation and accumulation of the self-assembling peptide monomer was observed and a minimum hydrogelator concentration required for gelation was identified. Subsequent formation of well defined nano- and microscale structures lead to self-supporting hydrogels at a range of substrate and enzyme concentrations. 1H NMR monitoring of the early self-assembly process revealed trends that were well in agreement with those identified using traditional methods (i.e. HPLC, CD, rheology) demonstrating 1H NMR spectroscopy can be used to non-invasively monitor the self-assembly of peptide hydrogels without damaging or perturbing the system.

2020 ◽  
Vol 7 (8) ◽  
pp. 1996-2010 ◽  
Author(s):  
Stephanie J. Franks ◽  
Kate Firipis ◽  
Rita Ferreira ◽  
Katherine M. Hannan ◽  
Richard J. Williams ◽  
...  

Self-assembling peptide hydrogels can effectively transport, hold and release therapeutic molecules in a spatially and temporally controlled manner and, in doing so, improve anti-cancer drug efficacy while reducing non-specific toxicity.


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.


Soft Matter ◽  
2020 ◽  
Vol 16 (28) ◽  
pp. 6599-6607 ◽  
Author(s):  
Pijush Singh ◽  
Souvik Misra ◽  
Nayim Sepay ◽  
Sanjoy Mondal ◽  
Debes Ray ◽  
...  

The self-assembly and photophysical properties of 4-nitrophenylalanine (4NP) are changed with the alteration of solvent and final self-assembly state of 4NP in competitive solvent mixture and are dictated by the solvent ratio.


2021 ◽  
Author(s):  
Bharti Koshti ◽  
Ramesh Singh ◽  
Vivekshinh Kshtriya ◽  
Shanka Walia ◽  
Dhiraj Bhatia ◽  
...  

<p>.<br></p><p>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.</p>


2020 ◽  
Vol 52 (8) ◽  
pp. 923-930 ◽  
Author(s):  
Hanae Arakawa ◽  
Kumi Takeda ◽  
Sayuri L. Higashi ◽  
Aya Shibata ◽  
Yoshiaki Kitamura ◽  
...  

AbstractVarious biofunctional hydrogel materials can be fabricated in aqueous media through the self-assembly of peptide derivatives, forming supramolecular nanostructures and their three-dimensional networks. In this study, we describe the self-assembly of new Fmoc-dipeptides comprising α-methyl-L-phenylalanine. We found that the position and number of methyl groups introduced onto the α carbons of the Fmoc-dipeptides by α-methyl-L-phenylalanine have a marked influence on the morphology of the supramolecular nanostructure as well as the hydrogel (network) formation ability.


Soft Matter ◽  
2015 ◽  
Vol 11 (26) ◽  
pp. 5353-5364 ◽  
Author(s):  
Virender Singh ◽  
Kirti Snigdha ◽  
Chandan Singh ◽  
Neeraj Sinha ◽  
Ashwani Kumar Thakur

Multiple factors that dictate the formation of a new polymorphic form of Fmoc–phenylalanine hydrogel.


RSC Advances ◽  
2014 ◽  
Vol 4 (58) ◽  
pp. 30654-30657 ◽  
Author(s):  
Rie Wakabayashi ◽  
Yuko Abe ◽  
Noriho Kamiya ◽  
Masahiro Goto

New GALA-related peptide amphiphiles were designed and the influence of their self-assembling propensity and the secondary structure on the membrane permeability was studied.


1995 ◽  
Vol 50 (4) ◽  
pp. 642-648 ◽  
Author(s):  
Rolf W. Saalfrank ◽  
Klaus Schobert ◽  
Stefan Trümmer ◽  
Alexander Wolski

The new bistetrazole 13 has been obtained by subsequent formation of the two heterocyclic units. In methanolic solution 13 reacts with zinc(II) acetate to yield the pseudo-meso-1 D-coordination polymer [ZnL2(MeOH)]n (n = ∞) 14. The structure of 14 was established by single crystal X-ray diffraction. The generation of the polymeric chain 14 is understandable, if intermediate formation of coordinatively unsaturated zinc(II) buildingblocks (Δ)-15 and (Λ)-15 is assumed. Alternating linkage of the self-complementary chiral monomers 15, across one cyanofunction each, leads to 14 with zinc being essentially octahedrally coordinated. Compared with polymeric compounds of similar bridging ligands, the Zn ··· N≡C-distance in 14 (225,7 pm) is short.


2020 ◽  
Vol 24 (1) ◽  
Author(s):  
Jeimmy González-Masís ◽  
Jorge M. Cubero-Sesin ◽  
Simón Guerrero ◽  
Sara González-Camacho ◽  
Yendry Regina Corrales-Ureña ◽  
...  

Abstract Background Collagen, the most abundant protein in the animal kingdom, represents a promising biomaterial for regenerative medicine applications due to its structural diversity and self-assembling complexity. Despite collagen’s widely known structural and functional features, the thermodynamics behind its fibrillogenic self-assembling process is still to be fully understood. In this work we report on a series of spectroscopic, mechanical, morphological and thermodynamic characterizations of high purity type I collagen (with a D-pattern of 65 nm) extracted from Wistar Hannover rat tail. Our herein reported results can be of help to elucidate differences in self-assembly states of proteins using ITC to improve the design of energy responsive and dynamic materials for applications in tissue engineering and regenerative medicine. Methods Herein we report the systematic study on the self-assembling fibrillogenesis mechanism of type I collagen, we provide morphological and thermodynamic evidence associated to different self-assembly events using ITC titrations. We provide thorough characterization of the effect of pH, effect of salts and protein conformation on self-assembled collagen samples via several complementary biophysical techniques, including circular dichroism (CD), Fourier Transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), atomic force microscopy (AFM), scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). Results Emphasis was made on the use of isothermal titration calorimetry (ITC) for the thermodynamic monitoring of fibrillogenesis stages of the protein. An overall self-assembly enthalpy value of 3.27 ± 0.85 J/mol was found. Different stages of the self-assembly mechanism were identified, initial stages take place at pH values lower than the protein isoelectric point (pI), however, higher energy release events were recorded at collagen’s pI. Denatured collagen employed as a control exhibited higher energy absorption at its pI, suggesting different energy exchange mechanisms as a consequence of different aggregation routes. Graphical abstract


Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1084 ◽  
Author(s):  
Shaoming Jin ◽  
Zhongyao Du ◽  
Pengjie Wang ◽  
Huiyuan Guo ◽  
Hao Zhang ◽  
...  

Folic acid has been widely introduced into nano-drug delivery systems to give nanoparticle-targeted characteristics. However, the poor water solubility of folic acid may hinder the exploitation of its ability to load antineoplastic drugs. In the present study, we designed a new folate derivative (FA-2-DG) synthesized from folic acid and 2-Deoxyglucose (2-DG). The aim of this study was to evaluate the self-assembly characteristics of FA-2-DG, and its ability of loading cisplatin. The critical micelle concentration was 7.94 × 10−6 mol L−1. Fourier transform infrared spectroscopy indicated that hydrogen bonding interaction is a main driving force for the self–assembly of FA-2-DG. The particle was stable in pure water or 0.5% bovine serum albumin dispersions. By forming a coordination bond, the particles assembled from FA-2-DG can load cisplatin. The loading efficiency was maximal when the molar ratio of FA-2-DG to cisplatin was 2:1.


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