A photoswitchable CENP-E inhibitor with single blue-green light to control chromosome positioning in mitotic cells.

Reversibly photoswitchable chemical tools have aided in the development of novel approaches in the biomedical field. The visible region of light should be ideal for the biological application of this approach because of its low phototoxicity and deep penetration depth compared to ultraviolet light. Herein, we report a photoswitchable centromere-associated protein E (CENP-E) inhibitor, which is controllable with low-energy blue-green light (around 500 nm) illumination.

Ratiometric sandwich-type assays for RNAs with a point mutation using benzo[a]pyrene-modified probes.

Benzo[a]pyrene-modified oligonucleotides were developed for the detection of RNAs with a point mutation. The probes produced two distinct fluorescence signals in response to single nucleotide differences in the RNA sequences, allowing for discrimination between the matched and single base mismatched RNA sequences in colorimetric and ratiometric manners.

In-cell chemical construction of a photoswitchable CENP-E using a photochromic covalent inhibitor.

An arylazopyrazole-based covalent inhibitor targeting the mitotic motor protein of centromere-associated protein E (CENP-E) was developed. Using this photoswitchable inhibitor, a photoswitchable CENP-E was chemically constructed in cells, which enabled to local control of mitotic cell division with light illumination.

Acetylmelodorinol isolated from Sphaerocoryne affinis seeds inhibits cell proliferation and activates apoptosis on HeLa cells.

Background: Cervical cancer is a major global health concern with a high prevalence in low- and middle-income countries. Natural products, particularly plant-derived compounds, have shown immense potential for developing anticancer drugs. In this study, we aimed to investigate the anticancer properties of the pericarp and seeds of Sphaerocoryne affinis fruit on human cervical carcinoma cells (HeLa) and isolate the bioactive compound from the active fraction.

Retardation of freezing of precooled, impinged water droplets on glass surfaces with microgrooves and silane coating.

Freezing impinged water droplets on glass surfaces cause serious problems such as reduced visibility of traffic lights and surveillance cameras. Droplets in the air associated with these issues are often at subzero temperatures. However, experimental results on the freezing of precooled impinged droplets are limited.

Distribution of class IId bacteriocin-producing Virgibacillus salexigens in various environments.

We performed several experiments using three strains of Virgibacillus salexigens, namely, P2, NT N53, and C-20Mo (DSM 11483), which were isolated from completely different sources, in relation to bacteriocin production ability. Results of whole-genome sequencing analysis revealed that all strains have very similar sequences encoding class IId bacteriocin. Although a partial amino acid sequence of the purified bacteriocin produced by strain P2 isolated from fermented food was previously reported, whole-genome sequencing and the N-terminal sequencing results in this study showed that its complete amino acid sequence consisted of 48 residues, which corresponded to that of the hypothetical bacteriocin encoded by the gene in Virgibacillus massiliensis strain Vm-5 (DSM 28587) isolated from the human gut.

Investigation on the Interactions between Self-Assembled β-Sheet Peptide Nanofibers and Model Cell Membranes.

Self-assembled peptide nanofibers (NFs) obtained from β-sheet peptides conjugated with drugs, including antigenic peptides, have recently attracted significant attention. However, extensive studies on the interactions of β-sheet peptide NFs with model cell membranes have not been reported. In this study, we investigated the interactions between three types of NFs, composed of PEG-peptide conjugates with different ethylene glycol (EG) lengths (6-, 12- and 24-mer), and dipalmitoylphosphatidylcholine (DPPC) Langmuir membranes.

Sandwich-type detection of nucleic acids by bioorthogonal SERS probes.

Nucleic acids in body fluids, such as circulating cell-free nucleic acids, viral DNA, and RNA have received much attention for their great potential as biomarkers in liquid biopsies of serious diseases. Although quantitative polymerase chain reaction (qPCR) has been traditionally used as a laboratory-based assay for measuring nucleic acids, there is a strong demand for techniques to qualitatively, rapidly, and simply measure the extremely low-abundance nucleic acids in order to realize the nucleic acid-based liquid biopsies. With this aim in mind, we developed a simple and highly sensitive sandwich-type assay for nucleic acids using a combination of surface-enhanced Raman scattering (SERS), which enhances Raman scattering by 10- to 10-fold, and bioorthogonal Raman tags, which generate signals in the biologically silent region (1800-2800 cm).

Development of a brain-permeable peptide nanofiber that prevents aggregation of Alzheimer pathogenic proteins.

Alzheimer's disease (AD) is proposed to be induced by abnormal aggregation of amyloidβ in the brain. Here, we designed a brain-permeable peptide nanofiber drug from a fragment of heat shock protein to suppress aggregation of the pathogenic proteins. To facilitate delivery of the nanofiber into the brain, a protein transduction domain from Drosophila Antennapedia was incorporated into the peptide sequence.

The Inhibition of Icing and Frosting on Glass Surfaces by the Coating of Polyethylene Glycol and Polypeptide Mimicking Antifreeze Protein.

The development of anti-icing, anti-frosting transparent plates is important for many reasons, such as poor visibility through the ice-covered windshields of vehicles. We have fabricated new glass surfaces coated with polypeptides which mimic a part of winter flounder antifreeze protein. We adopted glutaraldehyde and polyethylene glycol as linkers between these polypeptides and silane coupling agents applied to the glass surfaces.

Modulation of Cell Adhesion and Differentiation on Collagen Gels by the Addition of the Ovalbumin Secretory Signal Peptide.

Ovalbumin (OVA) is the most abundant protein in egg whites that is unnecessary in the egg yolk-based food industry. The development of OVA-based functional materials is of great interest. Collagen is a major component of the extracellular matrix.

Effect of the Hydrophilic-Hydrophobic Balance of Antigen-Loaded Peptide Nanofibers on Their Cellular Uptake, Cellular Toxicity, and Immune Stimulatory Properties.

Recently, nanofibers (NFs) formed from antigenic peptides conjugated to β-sheet-forming peptides have attracted much attention as a new generation of vaccines. However, studies describing how the hydrophilic-hydrophobic balance of NF components affects cellular interactions of NFs are limited. In this report, three different NFs were prepared by self-assembly of β-sheet-forming peptides conjugated with model antigenic peptides (SIINFEKL) from ovalbumin and hydrophilic oligo-ethylene glycol (EG) of differing chain lengths (6-, 12- and 24-mer) to investigate the effect of EG length of antigen-loaded NFs on their cellular uptake, cytotoxicity, and dendritic cell (DC)-stimulation ability.

Morphological Transformation of Peptide Nanoassemblies through Conformational Transition of Core-forming Peptides.

Morphological control of nanostructures that are composed of amphiphilic di- or tri-block molecules by external stimuli broadens their applications for molecular containers, nanoreactors, and controlled release materials. In this study, triblock amphiphiles comprising oligo(ethylene glycol), oligo(l-lysine), and tetra(l-phenylalanine) were prepared for the construction of nanostructures that can transform accompanying α-to-β transition of core-forming peptides. Circular dichroic (CD) measurements showed that the triblock amphiphiles adopted different secondary structures depending on the solvent environment: they adopt β-sheet structures in aqueous solution, while α-helix structures in 25% 2,2,2-trifluoroethanol (TFE) solution under basic pH conditions.

Effects of Winter Flounder Antifreeze Protein on the Growth of Ice Particles in an Ice Slurry Flow in Mini-Channels.

The control of ice growth in ice slurry is important for many fields, including (a) the cooling of the brain during cardiac arrest, (b) the storage and transportation of fresh fish and fruits, and (c) the development of distributed air-conditioning systems. One of the promising methods for the control is to use a substance such as antifreeze protein. We have observed and report here growth states of ice particles in both quiescent and flowing aqueous solutions of winter flounder antifreeze proteins in mini-channels with a microscope.

Asiatic Acid, Corosolic Acid, and Maslinic Acid Interfere with Intracellular Trafficking and N-Linked Glycosylation of Intercellular Adhesion Molecule-1.

The pentacyclic triterpenoid ursolic acid was previously shown to inhibit the intracellular trafficking of intercellular adhesion molecule-1 (ICAM-1) from the endoplasmic reticulum (ER) to the Golgi apparatus. In the present study, we further investigated the biological activities of three pentacyclic triterpenoids closely related to ursolic acid on the interleukin 1α-induced expression and intracellular trafficking of ICAM-1. In human lung adenocarcinoma A549 cells, asiatic acid, corosolic acid, and maslinic acid interfered with the intracellular transport of ICAM-1 to the cell surface.

Suppression of droplets freezing on glass surfaces on which antifreeze polypeptides are adhered by a silane coupling agent.

The development of ice-phobic, glass-substrate surfaces is important for many reasons such as poor visibility through the ice-covered windshields of vehicles. The present authors have developed new glass surfaces coated with a silane coupling agent and polypeptides whose amino-acid sequence is identical to a partial sequence of winter flounder antifreeze protein. We have conducted experiments on the freezing of sessile water droplets on the glass surfaces, and measured the droplet temperature, contact angle, contact area and surface roughness.

PE859, A Novel Curcumin Derivative, Inhibits Amyloid-β and Tau Aggregation, and Ameliorates Cognitive Dysfunction in Senescence-Accelerated Mouse Prone 8.

Aggregation of amyloid-β (Aβ) and tau plays a crucial role in the onset and progression of Alzheimer's disease (AD). Therefore, the inhibition of Aβ and tau aggregation may represent a potential therapeutic target for AD. Herein, we designed and synthesized both Aβ and tau dual aggregation inhibitors based on the structure of curcumin and developed the novel curcumin derivative PE859.

Fusion of polymeric material-binding peptide to cell-adhesion artificial proteins enhances their biological function.

Orientation-controlled protein immobilization on a solid substrate surface is important for the development of biomedical materials such as scaffolds used in tissue engineering. In this study, the authors demonstrated that the introduction of material-binding peptides (MBPs) in Arg-Gly-Asp (RGD)-fused artificial proteins called blocking peptide fragment (BPF), which are fragments (residues 419-607) of the molecular chaperone DnaK, enhances the oriented adsorption of proteins on the polymer surface and improves their cell adhesion capability. The authors used isotactic poly(methyl methacrylate) (it-PMMA) binding peptides (c02 peptide; ELWRPTR) as a model system.

Ice Growth Inhibition in Antifreeze Polypeptide Solution by Short-Time Solution Preheating.

The objective of this study is to enhance the inhibition of ice growth in the aqueous solution of a polypeptide, which is inspired by winter flounder antifreeze protein. We carried out measurements on unidirectional freezing of the polypeptide solution. The thickness of the solution was 0.

Ovalbumin Delivery by Guanidine-Terminated Dendrimers Bearing an Amyloid-Promoting Peptide via Nanoparticle Formulation.

Development of protein delivery systems is important for biomedical applications such as immunotherapy. Ovalbumin (OVA) is a major component of egg whites, and is a possible cause of egg allergy. In this study, OVA was used as a model protein to develop a delivery system using guanidine-terminated dendrimers (Gdn-den) bearing an amyloid-promoting peptide derived from the helix B (hB) region of OVA (hB-Gdn-den).