scholarly journals pH-Responsive Self-Assembly of Designer Aromatic Peptide Amphiphiles and Enzymatic Post-Modification of Assembled Structures

2021 ◽  
Vol 22 (7) ◽  
pp. 3459
Author(s):  
Rie Wakabayashi ◽  
Ayato Higuchi ◽  
Hiroki Obayashi ◽  
Masahiro Goto ◽  
Noriho Kamiya

Supramolecular fibrous materials in biological systems play important structural and functional roles, and therefore, there is a growing interest in synthetic materials that mimic such fibrils, especially those bearing enzymatic reactivity. In this study, we investigated the self-assembly and enzymatic post-modification of short aromatic peptide amphiphiles (PAs), Fmoc-LnQG (n = 2 or 3), which contain an LQG recognition unit for microbial transglutaminase (MTG). These aromatic PAs self-assemble into fibrous structures via π-π stacking interactions between the Fmoc groups and hydrogen bonds between the peptides. The intermolecular interactions and morphologies of the assemblies were influenced by the solution pH because of the change in the ionization states of the C-terminal carboxy group of the peptides. Moreover, MTG-catalyzed post-modification of a small fluorescent molecule bearing an amine group also showed pH dependency, where the enzymatic reaction rate was increased at higher pH, which may be because of the higher nucleophilicity of the amine group and the electrostatic interaction between MTG and the self-assembled Fmoc-LnQG. Finally, the accumulation of the fluorescent molecule on these assembled materials was directly observed by confocal fluorescence images. Our study provides a method to accumulate functional molecules on supramolecular structures enzymatically with the morphology control.

2019 ◽  
Vol 55 (5) ◽  
pp. 640-643 ◽  
Author(s):  
Rie Wakabayashi ◽  
Ayumi Suehiro ◽  
Masahiro Goto ◽  
Noriho Kamiya

Aromatic peptide amphiphiles self-assembled into fibrous materials with varied morphologies and enzymatic post-modification of the materials with proteins was achieved.


2014 ◽  
Vol 20 (3) ◽  
pp. 223-228 ◽  
Author(s):  
Qingbin Meng ◽  
Yingying Kou ◽  
Xin Ma ◽  
Lei Guo ◽  
Keliang Liu

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.


2008 ◽  
Vol 1135 ◽  
Author(s):  
Taiga Seki ◽  
Noriyoshi Arai ◽  
Taku Ozawa ◽  
Tomoko Shimada ◽  
Kenji Yasuoka ◽  
...  

ABSTRACTA coarse-grained model of peptide amphiphiles (PA) dissolved in aqueous solution was presented, where the effects of PA concentration, temperature and shear stress upon the self-assembly of PA were numerically studied by dissipative particle dynamics (DPD) simulation. We technically investigate the repulsion parameter aHW which indicates the repulsion force between the hydrophilic head of PA and water molecules, hence, at the same time, indicating the change in temperature. It was found that aHW played an important role in the self-assembly dynamics and in the resulting micro-structures of PA. By imposing shear strain on the simulation system, the formation of wormlike PA micelles was accelerated. The simulation results were in good agreement with our previous experimental results and the mechanism of shear-induced transition was proposed.


RSC Advances ◽  
2018 ◽  
Vol 8 (47) ◽  
pp. 26461-26468
Author(s):  
Taiga Seki ◽  
Noriyoshi Arai ◽  
Donguk Suh ◽  
Taku Ozawa ◽  
Tomoko Shimada ◽  
...  

Vapor pressure osmometry measurements and molecular simulation were carried out to investigate the self-assembly behavior of peptide amphiphiles. The results revealed that the head–water interaction plays an important role for their microstructure.


2016 ◽  
Vol 110 (3) ◽  
pp. 170a
Author(s):  
Hsien-Shun Liao ◽  
Peng Huang ◽  
Yuan Gao ◽  
Edward Cai ◽  
Ferenc Horkay ◽  
...  

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Xuan Song ◽  
Zhiwei Wang ◽  
Shiyu Tao ◽  
Guixia Li ◽  
Jie Zhu

Self-assembly of extracted collagen from swine trotter tendon under different conditions was firstly observed using atomic force microscopy; then the effects of collagen concentration, pH value, and metal ions to the topography of the collagen assembly were analyzed with the height images and section analysis data. Collagen assembly under 0.1 M, 0.2 M, 0.3 M CaCl2, and MgCl2 solutions in different pH values showed significant differences (P < 0.05) in the topographical properties including height, width, and roughness. With the concentration being increased, the width of collagen decreased significantly (P < 0.05). The width of collagen fibers was first increased significantly (P < 0.05) and then decreased with the increasing of pH. The collagen was assembled with network structure on the mica in solution with Ca2+ ions. However, it had shown uniformed fibrous structure with Mg2+ ions on the new cleaved mica sheet. In addition, the width of collagen fibrous was 31~58 nm in solution with Mg2+ but 21~50 nm in Ca2+ solution. The self-assembly collagen displayed various potential abilities to construct fibers or membrane on mica surfaces with Ca2+ ions and Mg2+ irons. Besides, the result of collagen self-assembly had shown more relations among solution pH value, metal ions, and collagen molecular concentration, which will provide useful information on the control of collagen self-assembly in tissue engineering and food packaging engineering.


2011 ◽  
Vol 64 (9) ◽  
pp. 1247 ◽  
Author(s):  
Angela M. H. Leung ◽  
Vanessa Ng ◽  
Yoon K. Ho ◽  
Lihan Zhou ◽  
Heng P. Too ◽  
...  

The self-assembly and gene delivery applications of poly(l-glutamate)-block-poly(2-(diethylamino)ethyl methacrylate) (PLG18-b-PDEAEMA37) were investigated. Owing to the functional groups on the polymer, an amine and a carboxylic acid group, the self-assembly process is dependent on the solution pH, where the critical micelle concentration was determined to be 61 and 320 μg mL–1 at high and low pH, respectively. The block copolymer forms positively charged vesicles at low pH with a hydrodynamic radius of 90 nm and negatively charged vesicles at high pH with a hydrodynamic radius of 50 nm. At the isoelectric point of 4.9, PLG-b-PDEAEMA was found to form larger micellar aggregates with a hydrodynamic radius of 180 nm because of the presence of both positive and negative charges. The complexation between PLG-b-PDEAEMA and DNA was studied at physiological pH as well as at low and high pH. DNA is condensed most effectively at pH 3, at an N/P ratio of 5, whereas at pH 7 and 10, an N/P ratio of 20 is required. However, in-vitro studies at physiological pH using neuroblastoma cells did not show substantial gene expression.


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