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Self-assembling peptide

Atanu Das, Dmitrii E Makarov
Protein aggregation and amyloid formation are implicated in many diseases as well as in other biological phenomena. Recent studies have suggested that amyloid formation of tumor suppressor p53 can lead to loss of its physiological function, resulting in accelerated cancer progression. Design of cancer therapeutics, therefore, requires understanding of the mechanism of p53 aggregation. Here, we have employed atomistic simulations to characterize the aggregation process of the aggregation-prone (as suggested by experimental studies) p53 fragment (LTIITLE, 252-258) and to assess the efficiency of its I254R mutant as an aggregation suppressor...
October 24, 2016: Journal of Physical Chemistry. B
Søren B van Witteloostuijn, Søren L Pedersen, Knud J Jensen
Peptides and proteins constitute a vast pool of excellent drug candidates. Evolution has equipped these molecules with superior drug-like properties such as high specificity and potency. However, native peptides and proteins suffer from an inadequate pharmacokinetic profile, and their outstanding pharmacological potential can only be realized if this issue is addressed during drug development. To overcome this challenge, a variety of half-life extension techniques relying on covalent chemical modification have been developed...
October 24, 2016: ChemMedChem
Jun-Qing Situ, Xiao-Juan Wang, Xiu-Liang Zhu, Xiao-Ling Xu, Xu-Qi Kang, Jing-Bo Hu, Chen-Ying Lu, Xiao-Ying Ying, Ri-Sheng Yu, Jian You, Yong-Zhong Du
Specific delivery of chemotherapy drugs and magnetic resonance imaging (MRI) contrast agent into tumor cells is one of the issues to highly efficient tumor targeting therapy and magnetic resonance imaging. Here, A54 peptide-functionalized poly(lactic-co-glycolic acid)-grafted dextran (A54-Dex-PLGA) was synthesized. The synthesized A54-Dex-PLGA could self-assemble to form micelles with a low critical micelle concentration of 22.51 μg. mL(-1) and diameter of about 50 nm. The synthetic A54-Dex-PLGA micelles can encapsulate doxorubicin (DOX) as a model anti-tumor drug and superparamagnetic iron oxide (SPIO) as a contrast agent for MRI...
October 24, 2016: Scientific Reports
Dawei Xu, Qian Ran, Yang Xiang, Jiang Linhai, Britannia M Smith, Fadi Bou-Abdallah, Reidar Lund, Zhongjun Li, He Dong
A significant challenge associated with systemic delivery of cationic antimicrobial peptides and polymers lies in their limited hemocompatibility toward vast numbers of circulating red blood cells (RBCs). Supramolecular assembly of cationic peptides and polymers can be an effective strategy to develop an array of antimicrobial nanomaterials with tunable material structures, stability and thus optimized bioactivity to overcome some of the existing challenges associated with conventional antimicrobials. In this work, we will demonstrate the supramolecular design of self-assembling antimicrobial nanofibers (SAANs) which have tunable supramolecular nanostructures, stability, internal molecular packing and surface chemistry through self-assembly of de novo designed cationic peptides and peptide-PEG conjuguates...
2016: RSC Advances
Caitlin D Allen, A James Link
Lasso peptides exist naturally in a threaded state as [1]rotaxanes, and we reasoned that lasso peptides cleaved in their loop region could serve as building blocks for catenanes. Mutagenesis of the lasso peptide microcin J25 (MccJ25) with two cysteine residues followed by cleavage of the peptide with trypsin led to a [2]rotaxane structure that self-assembled into a [3]catenane and [4]catenanes at room temperature in aqueous solution. The [3]catenane represents the smallest ring size of a catenane composed solely of polypeptide segments...
October 21, 2016: Journal of the American Chemical Society
I Caglar Tanrikulu, Audrey Forticaux, Song Jin, Ronald T Raines
Sticky-ended DNA duplexes can associate spontaneously into long double helices; however, such self-assembly is much less developed with proteins. Collagen is the most prevalent component of the extracellular matrix and a common clinical biomaterial. As for natural DNA, the ~10(3)-residue triple helices (~300 nm) of natural collagen are recalcitrant to chemical synthesis. Here we show how the self-assembly of short collagen-mimetic peptides (CMPs) can enable the fabrication of synthetic collagen triple helices that are nearly a micrometre in length...
November 2016: Nature Chemistry
Fengyang Xu, Jie Liu, Jian Tian, Lingfeng Gao, Xiaju Cheng, Yue Pan, Ziling Sun, Xinming Li
In this work, we reported the generation of a novel supramolecular hydrogelator from a peptide derivative which consisted of a structural motif (e.g., Fc-FF) for supramolecular self-assembly and a functional moiety (e.g., RGD) for integrin binding. Following self-assembly in water at neutral pH, this molecule firstly tended to form metastable spherical aggregates, which subsequently underwent a morphological transformation to form high-aspect-ratio nanostructures over 2 h when aged at room temperature. More importantly, because of the presence of nanoscale RGD clusters on the surface of nanostructures, the self-assembled nanomaterials (e...
October 19, 2016: ACS Applied Materials & Interfaces
Kei Ando, Shiro Imagama, Zenya Ito, Kazuyoshi Kobayashi, Tetsuro Hida, Hiroaki Nakashima, Kenyu Ito, Mikito Tsushima, Yoshimoto Ishikawa, Akiyuki Matsumoto, Koji Nishida, Yoshihiro Nishida, Naoki Ishiguro
STUDY DESIGN: Self-assembling peptide gel (SPG-178) provides new evidence for the role of a scaffold for treatment of the spinal cord through induction of neuroprotective factors. OBJECTIVE: To verify the reproducibility of SPG-178 as scaffold after spinal cord injury, we examine the characteristics of SPG-178 and protective effect on neural cells in vitro and in vivo. SUMMARY OF BACKGROUND DATA: The central nervous system extracellular matrix may play a role in maintenance of the neuronal network by inhibiting axonal growth and suppressing formation of additional inadequate synapses...
October 15, 2016: Spine
Karin Kornmueller, Bernhard Lehofer, Claudia Meindl, Eleonore Fröhlich, Gerd Leitinger, Heinz Amenitsch, Ruth Prassl
Self-assembling amphiphilic designer peptides have been successfully applied as nanomaterials in biomedical applications. Understanding molecular interactions at the peptide-membrane interface is crucial, since interactions at this site often determine (in)compatibility. The present study aims to elucidate how model membrane systems of different complexity (in particular single-component phospholipid bilayers and lipoproteins) respond to the presence of amphiphilic designer peptides. We focused on two short anionic peptides, V₄WD₂ and A₆YD, which are structurally similar, but showed a different self-assembly behavior...
October 14, 2016: Biomacromolecules
Benjamin P Partlow, Mehran Bagheri, James L Harden, David L Kaplan
Native silk fibers exhibit strength and toughness that rival those of the best synthetic fibers. Importantly, the silkworm is able to spin these fibers using only water as a solvent with fine control of applied shear, drawing, pH and salt concentrations to efficiently convert the spinning dope into a fiber. This is in contrast to synthetic polymers that often require organic solvents and extreme processing conditions. Further insight is still needed into the mechanisms by which silkworms are capable of spinning such tough fibers...
October 13, 2016: Biomacromolecules
T N Figueira, L M Palermo, A S Veiga, D Huey, C A Alabi, N C Santos, J C Welsch, C Mathieu, B Horvat, S Niewiesk, A Moscona, M A R B Castanho, M Porotto
: Measles virus (MV) infection is undergoing resurgence and remains one of the leading causes of death among young children worldwide despite the availability of an effective measles vaccine. MV infects its target cells by coordinated action of the MV hemagglutinin (H) and fusion (F) envelope glycoproteins; upon receptor engagement by H, the pre-fusion F undergoes a structural transition, extending and inserting into the target cell membrane and then re-folding into a post-fusion structure that fuses the viral and cell membranes...
October 12, 2016: Journal of Virology
Shuyun Liu, Lanlan Zhang, Jingqiu Cheng, Yanrong Lu, Jingping Liu
Inflammatory response is a major cause of grafts dysfunction in islet transplantation. Hepatocyte growth factor (HGF) had shown anti-inflammatory activity in multiple diseases. In this study, we aim to deliver HGF by self-assembling peptide/heparin (SAP/Hep) hybrid gel to protect β-cell from inflammatory injury. The morphological and slow release properties of SAPs were analyzed. Rat INS-1 β-cell line was treated with tumor necrosis factor α in vitro and transplanted into rat kidney capsule in vivo, and the viability, apoptosis, function, and inflammation of β-cells were evaluated...
2016: International Journal of Nanomedicine
Seema Singh, Pravin Jha, Vandana Singh, Kislay Sinha, Sahid Hussain, Manoj K Singh, Prolay Das
Non-targeted photosensitizers lack selectivity that undermines the potential use of photodynamic therapy (PDT). Herein, we report the DNA mediated assembly of a ZnSe/ZnS quantum dot (QD)-photosensitizer (PS)-Mucin 1(MUC1) aptamer conjugate for targeting the MUC1 cancer biomarker and simultaneous generation of reactive oxygen species (ROS). A photosensitizer, protoporphyrin IX (PpIX), was conjugated to a single stranded DNA and self-assembled to a complementary strand that was conjugated to a QD and harboring a MUC1 aptamer sequence...
October 10, 2016: Integrative Biology: Quantitative Biosciences From Nano to Macro
I R Sasselli, C G Pappas, E Matthews, T Wang, N T Hunt, R V Ulijn, T Tuttle
Despite progress, a fundamental understanding of the relationships between the molecular structure and self-assembly configuration of Fmoc-dipeptides is still in its infancy. In this work, we provide a combined experimental and computational approach that makes use of free energy equilibration of a number of related Fmoc-dipeptides to arrive at an atomistic model of Fmoc-threonine-phenylalanine-amide (Fmoc-TF-NH2) which forms twisted fibres. By using dynamic peptide libraries where closely related dipeptide sequences are dynamically exchanged to eventually favour the formation of the thermodynamically most stable configuration, the relative importance of C-terminus modifications (amide versus methyl ester) and contributions of aliphatic versus aromatic amino acids (phenylalanine F vs...
October 12, 2016: Soft Matter
Francesca Biscaglia, Elisa Frezza, Enrico Zurlo, Marina Gobbo
The solvent-promoted aggregation of porphyrins covalently linked to medium length peptides occurs with the formation of chiral supramolecular structures if the peptide chain can adopt an α-helical secondary structure. The circular dichroism spectra of different porphyrin-peptide conjugates show that the chiral arrangement of the porphyrins in the aggregates does not depend on the screw-sense of the peptide helix. Experimental evidence and molecular dynamic simulations suggest that the linker between the porphyrin and the peptide helix is responsible for the overall chirality of supramolecular structures...
October 12, 2016: Organic & Biomolecular Chemistry
Juan Wang, Guizhi Shen, Kai Ma, Tifeng Jiao, Kai Liu, Xuehai Yan
Concave nanospheres based on the self-assembly of simple dipeptides not only provide alternatives for modeling the interactions between biomacromolecules, but also present a range of applications for purification and separation, and delivery of active species. The kinetic control of the peptide assembly provides a unique opportunity to build functional and dynamic nanomaterials, such as concave nanospheres. In this work, we report dipeptide-based concave nanospheres with structures from crescent-like to solid interior by interfacially controlled self-assembly in combination with covalent formation of building blocks, driven by synergistic thermodynamic and kinetic control...
October 10, 2016: Physical Chemistry Chemical Physics: PCCP
K Koss, C Tsui, L D Unsworth
(RADA)4 self-assembling peptides (SAPs) are promising for neural nanoscaffolds with on-demand drug delivery capabilities due to their automated synthesis, in-situ assembly, and potential for interaction with and release of biomolecules. Neuroinflammation cued on-demand drug release, due to up-regulated proteases, may well be vital in the treatment of several neurological diseases. In these conditions, releasing neurotrophic growth factors (NTFs) could potentially lead to neuroprotection and neurogenesis. As such, (RADA)4 was made with the high and low activity matrix metalloproteinase 2 (MMP-2) cleaved sequences, GPQG+IASQ (CP1) and GPQG+PAGQ (CP2), the brain-derived NTF secretion stimulating peptide MVG (DP1) and the ciliary NTF analogue DGGL (DP2)...
October 5, 2016: Journal of Controlled Release: Official Journal of the Controlled Release Society
Raffaele Pugliese, Fabrizio Gelain
Peptidic biomaterials represent a particularly exciting topic in regenerative medicine. Peptidic scaffolds can be specifically designed for biomimetic customization for targeted therapy. The field is at a pivotal point where preclinical research is being translated into clinics, so it is crucial to understand the theory and describe the status of this rapidly developing technology. In this review, we highlight major advantages and current limitations of self-assembling peptide-based biomaterials, and we discuss the most widely used classes of assembling peptides, describing recent and promising approaches in tissue engineering, drug delivery, and clinics...
October 4, 2016: Trends in Biotechnology
Xiaowen Wu, Suntharavathanan Mahalingam, Sarah Kay VanOosten, Cate Wisdom, Candan Tamerler, Mohan Edirisinghe
Aligned poly(l-lactide)/poly(methyl methacrylate) binary blend fibers and mats loaded with a chimeric green fluorescence protein having a bioactive peptide with hydroxyapatite binding and mineralization property are prepared by pressurized gyration. The effect of processing parameters on the product morphologies, and the shape memory properties of these samples are investigated. Integration of hydroxyapatite nanoparticles into the fiber assembly is self-directed using the hydroxyapatite-binding property of the peptide genetically engineered to green fluorescence protein...
September 26, 2016: Macromolecular Bioscience
Jérémy Ruiz, Régis Boehringer, Marcel Grogg, Jésus Raya, Alicia Schirer, Corinne Crucifix, Petra Hellwig, Patrick Schultz, Vladimir Torbeev
Polymorphism is a common property of amyloid fibers that complicates their detailed structural and functional studies. Here we report experiments illustrating the chemical principles that enable the formation of amyloid polymorphs with distinct stoichiometric composition. Using appropriate covalent tethering we programmed self-assembly of a model peptide corresponding to the [20-41]-fragment of human β2-microglobulin into fibers with either trimeric or dimeric amyloid cores. Using a set of biophysical and biochemical methods we demonstrated their distinct structural, morphological and templating properties...
September 26, 2016: Chembiochem: a European Journal of Chemical Biology
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