Nanopeptides

Brain injury is a devastating medical condition and represents a major health problem. Tissue and organ reconstruction have been regarded as promising therapeutic strategies. Here, we propose a regenerative methodology focusing on the provision of functionalized nanopeptide scaffolds to facilitate angiogenesis and neurogenesis at the brain injury site. The peptide RADA16-SVVYGLR undergoes self-assembly to construct an interconnected network with intertwining nanofibers, and can be controlled to display various physicochemical properties by the adjustment of microenvironmental factors such as pH and ion concentration...

Prediction of peptide binding on specific human leukocyte antigens (HLA) has long been studied with successful results. We herein describe the effects of entropy and dynamics by investigating the binding stabilities of 10 nanopeptides on various HLA Class I alleles using a theoretical model based on molecular dynamics simulations. The fluctuational entropies of the peptides are estimated over a temperature range of 310-460 K. The estimated entropies correlate well with experimental binding affinities of the peptides: peptides that have higher binding affinities have lower entropies compared to non-binders, which have significantly larger entropies...

Cell-based partial pulp regeneration is one of the promising approaches to obtain newly formed functional dentin-pulp complex. It relies on the preservation of the healthy tissue while regenerating the damaged pulp. The aim of this study was to investigate whether this regenerative process could be achieved by implanting porcine dental pulp cells (pDPCs) in pulp defects in the minipig. By split-mouth model, self-assembling injectable nanopeptide hydrogel, with and without pDPCs, was implanted after cameral pulpotomy in premolars and molars...

OBJECTIVES: In order to grow cells in a three-dimensional (3D) microenvironment, self-assembling peptides, such as PuraMatrix, have emerged with potential to mimic the extracellular matrix. The aim of the present study was to investigate the influence of the self-assembling peptide on the morphology, survival, proliferation rate, migration potential, and differentiation of human meningioma stem-like cells (hMgSCs). MATERIALS AND METHODS: The efficacy of a novel method for placing hMgSCs in PuraMatrix (the injection approach) was compared to the encapsulation and surface plating methods...

Theoretical studies, including quantum chemistry (QM) calculations and 25 ns molecular dynamic (MD) simulations, were performed on two types of hybrid cyclic nanopeptides (HCNPs) that are constructed of tren-capped cryptand (HCNP1) and 1,3,5-triethylbenzene-capped cryptand (HCNP2) for selective complex formation with OAC- , NO3 - , HSO4 - , F- , Br- , and Cl- ions in the gas phase and DMSO. Obtained data by M05-2X, M05-2X-D3, B3LYP, and B3LYP-D3 functionals indicated that HCNPs form a stable complex with F- in comparison to other ions...

OBJECTIVE: Oxytocin, a nanopeptide secreted by the posterior pituitary gland, has well-established uterotonic activity. Its role in initiating the vigorous and regular contractions of the first stage of labor is still controversial. We report four cases of panhypopituitarism who had spontaneous onset of labor, undermining the role of maternal oxytocin in the first phase of labor. STUDY DESIGN: Four women with no residual pituitary function conceived through ovulation induction and were treated throughout pregnancy with thyroid replacement therapy, desmopressin and glucocorticoids...

The use of local agents to achieve hemostasis of bone that does not interfere with repair and recovery is a complex and emergency subject in surgery. In this study, the dual functional biodegradable self-assembling nanopeptide (SAP) RADA16-I was synthesized by solid phase synthesis and was shown to exhibit immediate hemostasis and accelerative osteosis. The RADA16-I showed good performance as a hemostatic agent, which was investigated by comparison with the effects of bone wax in the ilium bone defect model of New Zealand rabbits...

A novel antibacterial ointment using bacitracin, specific for Gram-positive bacteria, and gramicidin S, a highly toxic antibacterial peptide, was here developed showing broad-spectrum antibacterial activities against pathogenic strains with less toxicity after self-assembly into nanofiber structures. Such structures were confirmed with scanning electron microscopy and CD analyses. In addition, in silico studies using docking associated with molecular dynamics were carried out to obtain information about fiber structural oligomerization...

The chaotic spatial disarray due to extracellular matrix expansion disrupts cardiomyocytes interaction and causes arrhythmia. We hypothesized that disordered nanopeptide scaffolds can mimic the chaotic spatial disarray related to cardiac fibrosis and have arrhythmogenic effects on cardiomyocytes. Primary mouse cardiomyocytes were cultured in 2D traditional and 3D nanopeptide hydrogel scaffold systems. Cardiomyocytes in 3D scaffolds showed irregular spontaneous contractile activity as compared with 2D culture controls...

Traumatic injury or surgery may trigger extensive bleeding. However, conventional hemostatic methods have limited efficacy and may cause surrounding tissue damage. In this study, we use self-assembling peptides (SAPs) and specifically extend fragments of functional motifs derived from fibronectin and laminin to evaluate the capability of these functionalized SAPs in the effect of hemostasis and liver tissue regeneration. From the results, these peptides can self-assemble into nanofibrous network structure and gelate into hydrogel with pH adjustment...

Humans are intensely social animals, and healthy social relationships are vital for proper mental health (see Lim and Young, 2006). By using animal models, the behavior, mental, and physiological processes of humans can be understood at a level that cannot be attained by studying human behavior and the human brain alone. The goals of this review are threefold. First, we define affiliative social behavior and describe the primary relationship types in which affiliative relationships are most readily observed--the mother-infant bond and pair-bonding...

Twenty-seven nanopeptides derived from the matrix (M) protein of porcine reproductive and respiratory syndrome virus (PRRSV) were screened for their ability to elicit a recall interferon-γ (IFN-γ) response from the splenocytes of BALB/c mice following DNA vaccination and a booster vaccination with recombinant vaccinia virus rWR-PRRSV-M. We identified two peptides (amino acid residues K93FITSRCRL and F57GYMTFVHF) as CD8+ cytotoxic T lymphocyte (CTL) epitopes. These peptides elicited significant numbers of IFN-γ secreting cells, compared with other M nonapeptides and one irrelevant nonapeptide...

Biological functions of duck basic protein small 1 (dBPS(1)) and 2 (dBPS(2)) were investigated by in vitro experiments. Results of agarose gel retardation assay indicated that dBPS(1) and dBPS(2) associate with RNA. Addition of NaCl or urea induced partial dissociation of dBPS(1)/dBPS(2)-RNA complex, implying that electrostatic interaction, hydrophobic interaction, and hydrogen bonds are involved in the association of dBPS(1)/dBPS(2) to RNA. dBPS(1) and dBPS(2) inhibited pancreatic lipase activity with the fifty percent inhibitory concentration (IC(50)) of 250 and 100 μg/mL, respectively...

Vasopressin is a modulator of salt and water reabsorption, with known effects in the thick ascending limb and the collecting duct. Pedersen et al. present evidence that vasopressin administration increases the phosphorylation of the apical thiazide-sensitive Na(+)-Cl(-) cotransporter in the distal convoluted tubule. These effects appear to be independent of the renin-angiotensin system and to be mediated by the intracellular kinase SPAK. These observations expand the vasopressin-sensitive region of the nephron...

Vibrio vulnificus, a ubiquitous microorganism in aquatic environments, causes serious septicemia to the immunocompromised host. In addition to protoheme, this species can utilize Fe-TCPP [ferric tetrakis (4-carboxyphenyl) porphine] as an iron source. In the present study, heme c bound covalently to the protein in cytochrome c, as well as the Fe-TCPP complex formed with a nanopeptide with a high affinity, was found to be useful iron sources for V. vulnificus. This bacterium was also revealed to use Zn-TCPP as a single zinc source...

For many decades, rigorous efforts have been made worldwide to develop a successful oral insulin-delivery system, which still remains an elusive goal. However, over the past few years, tremendous understanding has evolved in the development of biocompatible and biodegradable polymers, synthesis of nanopeptide delivery systems, biocompatibility and its cellular uptake mechanisms. With these advancements, efforts are being directed toward nanoparticle-based oral peptide-delivery systems. It is established that nanoparticles enhance oral bioavailability by facilitating insulin uptake via a transcellular or paracellular pathway...

The brain nanopeptide arginine vasotocin (AVT) and its mammalian homolog arginine vasopressin are involved in the regulation of social and reproductive behavior. We investigated the relationship between social rank formation and the brain AVT system in the false clown anemonefish (Amphiprion ocellaris), which forms a social rank that leads to sex differentiation in higher-ranked individuals. Tanks of three sexually immature fish were kept for 90 days and each fish's behavior was observed once a month. The social rank of each individual was distinguishable by behavior, but gonadosomatic index (GSI) did not differ significantly...

A colostral proline-rich polypeptide complex (PRP) consisting of over 30 peptides shows beneficial effects in Alzheimer's disease (AD) patients when administered in the form of sublinqual tablets called Colostrinin. The aim of the present studies was to investigate whether nanopeptide fragment of PRP (NP) - one of the PRP complex components can affect aggregation of amyloid beta (Abeta1-42). The effect of NP on Abeta aggregation was studied using Thioflavin T (ThT) binding, atomic force microscopy, and analyzing circular dichroism spectra...

The high molecular weight glutenin subunit (HMW-GS) pair 1Bx13 + 1By16are recognized to positively correlate with bread-making quality; however, their molecular data remain unknown. In order to reveal the mechanism by which 1By16 and 1Bx13 creates high quality, their open reading frames (ORFs) were amplified from common wheat Atlas66 and Jimai 20 using primers that were designed based on published sequences of HMW glutenin genes. The ORF of 1By16 was 2,220 bp, deduced into 738 amino acid residues with seven cysteines including 59 hexapeptides and 22 nanopeptides motifs...

The nanoscale peptide YSGVCHTDLHAWHGDWPLPVK exhibits molecular chaperone activity and prevents protein aggregation under chemical and/or thermal stress. Here, His mutations of this peptide and their impact on chaperone activity were evaluated using theoretical techniques. Molecular dynamic (MD) simulations with simulated annealing (SA) of different mutant nanopeptides were employed to determine the contribution of the scaffolding His residues (H45, H49, H52), when mutated to Pro, on chaperone action in vitro...