Publications by authors named "Nokihara K"

One cyclic peptide immobilized on one gel-type bead has been employed for the discovery of both interacting peptides and/or medicinal medium-sized molecules. Although high-throughput characterization of recognized peptides has been a bottleneck, here, we describe direct liberation from beads by a one-pot reaction using 2-nitro-5-thiocyanatobenzoic acid followed by mass spectrometry to realize faster and routine sequencing of the peptide on the beads. This is useful for the investigation of protein-protein interactions as well as discovery of drug candidates.

View Article and Find Full Text PDF

Medium sized molecules such as peptides and macrocycles have recently drawn much attention as potent sources of medicinal lead compounds, whereas the possibility of obtaining a practical drug from them remains limited. The present paper describes a concept of discovering novel medicinal targets or binding modes as well as lead compounds by the one-peptide-on-one-bead (OPOB) technology for comprehensive screening. The difficulty and problems in conventional drug discovery methods that generally deal with one predetermined target are considered.

View Article and Find Full Text PDF

Because weevils are the most damaging pests of sweetpotato, the development of cultivars resistant to weevil species is considered the most important aspect in sweetpotato breeding. However, the genes and the underlying molecular mechanisms related to weevil resistance are yet to be elucidated. In this study, we performed an RNA sequencing-based transcriptome analysis using the resistant Kyushu No.

View Article and Find Full Text PDF

Vascularization is one of the key steps for engraftment in regenerative medicine. Previously one of the authors had discovered peptides exhibiting significant angiogenic activities designated AGP and elucidated the active core. For neovascularization basic fibroblast growth factor is used although permeation can be envisaged.

View Article and Find Full Text PDF

We apply the GWAS to sweet potato genome, and identified the SNPs associated with yield and weevil resistance. The sweet potato (Ipomoea batatas (L.) Lam) is a highly heterozygous, outcrossing, polyploid species, which presents challenges for genetic analysis.

View Article and Find Full Text PDF

Melanin is rigidly constructed by several nitrogen-containing aromatic rings, and its excess accumulation in skin tissue is closely associated with melanosis. Although visible lasers (wavelength: 600-1000 nm) are conventionally used for the photo-thermolysis of melanocyte, several pigmented nevi are difficult to be treated. Here, we propose an alternate method for targeting the molecular structure of melanin using an infrared free-electron laser (FEL) tuned to 5.

View Article and Find Full Text PDF

A fundamental method has been developed focusing on a facile and rapid examination of periodontal disease. Periodontal disease is an oral disease thought to affect 80% of adults, and early detection with treatment is desirable for the improvement of the quality of life. Unfortunately conventional methods are not consistent as the disease is caused by a number of undefined bacteria and detection relies on the skills of the dentist.

View Article and Find Full Text PDF

Relatively larger scale peptide libraries immobilized on a gel-type solid support consisting of 24 natural and non-natural amino acids by the "split and combine method" have been constructed to find interacting molecules. The diversity was ca. 200 millions of hexapeptides with cysteinyl residues forming cyclotide.

View Article and Find Full Text PDF

Pyrrole-Imidazole (PI) polyamides bind to specific DNA sequences in the minor groove with high affinity. Specific DNA labeling by PI polyamides does not require DNA denaturation with harsh treatments of heat and formamide and has the advantages of rapid and less disruptive processing. Previously, we developed tandem hairpin PI polyamide probes (TH59 series), which label telomeres in cultured cell lines more efficiently than conventional methods, such as fluorescence in situ hybridization (FISH).

View Article and Find Full Text PDF

Peptidoglycan is a giant bag-shaped molecule essential for bacterial cell shape and resistance to osmotic stresses. The activity of a large number of bacterial surface proteins involved in cell growth and division requires binding to this macromolecule. Recognition of peptidoglycan by immune effectors is also crucial for the establishment of the immune response against pathogens.

View Article and Find Full Text PDF

Interaction between proteins (as analytes) and de novo designed structured peptides as capture molecules cause structural changes, which are reflected in fluorescent-intensity changes of labeled peptides in a dose dependent manner. In contrast to conventional detection methods our detection system does not involve the detection of specific molecules themselves in a 1:1 manner, but uses the principle of the differences in fluorescent intensity changes of capture peptides upon addition of analytes. Instead of the use of secondary antibodies we have attempted monitoring these structural changes by an array of de novo designed synthetic and structured peptides.

View Article and Find Full Text PDF

A polyamide containing N-methylpyrrole (Py) and N-methylimidazole (Im), designated PIPA, binds with high affinity and specificity to specific nucleotide sequences in the minor groove of double-helical DNA. Based on a recent report of the synthesis of PIPA for telomere visualization, the present paper focused on the size of the connecting part (hinge region) of two PIPA segments of the tandem hairpin PIPA, Dab(Im-Im-Py)-Py-Py-Py-Im-[Hinge]-Dab(Im-Im-Py)-Py-Py-Py-Im-βAla-NH(CH2)3N(CH3)-(CH2)3NH-[Dye]. The present paper also describes the characterization of binding by measuring the thermal melting temperature and surface plasmon resonance and by specific staining of telomeres (TTAGGG)n in human cells.

View Article and Find Full Text PDF

The co-existence of certain peptides influenced the kinetic rate of aggregation and the lag-time of fibril formation of rbPrP. Using recently developed structural conversion assay system, peptides have been screened from bovine brain peptide library. Peptide sequences of positive components have been elucidated by mass spectrometry and chemically synthesized to confirm actions.

View Article and Find Full Text PDF

Structural changes of proteins are thought to involve specific protein-peptide interactions, thus we hypothesize that certain peptides may contribute to the conformational change of prion proteins. Hence peptide libraries were constructed from partial digests of bovine brain. Using a recently developed conversion assay method, we have screened peptides responsible for structural conversion.

View Article and Find Full Text PDF

With the increase in molecular diagnostics and patient-specific therapeutic approaches, the delivery and targeting of imaging molecules and pharmacologically active agents gain increasing importance. The ideal delivery system does not exist yet. The realization of two features is indispensable: first, a locally high concentration of target-specific diagnostic and therapeutic molecules; second, the broad development of effective and safe carrier systems.

View Article and Find Full Text PDF

Characteristic differences of prions may account for the conformational diversity of the pathogenic isoform of prion protein (PrP(Sc)). Here, we applied a protein detection procedure by using fluorescent-labelled peptides for detecting PrP(Sc). Five prion protein (PrP) related peptides were found to change significantly their fluorescent intensities with prion-affected animal samples.

View Article and Find Full Text PDF

Progress in genomics and proteomics attended to the door for better understanding the recent rapid expanding complex research field of metabolomics. This trend in biomedical research increasingly focuses to the development of patient-specific therapeutic approaches with higher efficiency and sustainability. Simultaneously undesired adverse reactions are avoided.

View Article and Find Full Text PDF

Focusing on drug discovery non-proteinogenic amino acids have often been used as important building blocks for construction of compound libraries in the filed of combinatorial chemistry and chemical biology. Highly homogeneous L: -mimosine, α-amino-β-(3-hydoxy-4-oxo-1,4-dihydropyridin-1-yl)-propanoic acid, a non-proteinogenic amino acid, has been successfully isolated and purified on an industrial scale from wild leaves of Leucaena (Leucaena leucocephala de Wit) which is a widely distributed legume in Okinawa, a sub-tropical island in Japan. Optical purity determinations used for quality control have been established through diastereomer formation.

View Article and Find Full Text PDF

Since human serum albumin has one sulfhydryl group and 17 disulfides, reactive sulfhydryl groups give rise to heterogeneity. The present paper presents a comparison of sulfhydryl heterogeneity in human serum albumin and recombinant human serum albumin for clinical use. Low molecular weight sulfhydryl compounds were identified from both sources.

View Article and Find Full Text PDF

Aim: To determine the effect of pituitary adenylate cyclase-activating polypeptide (PACAP) on left gastric artery (LGA) flow and to unveil the structural or functional important sites that may be critical for discrimination of different receptor subtypes.

Methods: Peptides, including PACAP-27, PACAP-38, amino acid substituted PACAP-27 and C-terminus truncated analogues PACAP (27-38), were synthesized by a simultaneous multiple solid-phase peptide synthesizer. Flow probes of an ultrasound transit-time blood flowmeter were placed around the LGA of beagle dogs.

View Article and Find Full Text PDF

The identification of HIV-1 cytotoxic T lymphocyte (CTL) epitopes presented by each HLA allele and the characterization of their CTL responses are important for the study of pathogenesis of AIDS and the development of a vaccine against it. In the present study, we focused on identification and characterization of HIV-1 epitopes presented by HLA-B*5401, which is frequently found in the Asian population, because these epitopes have not yet been reported. We identified these epitopes by using 17-mer overlapping peptides derived from HIV-1 Gag, Pol, and Nef.

View Article and Find Full Text PDF

Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) have opposite actions on the gallbladder; PACAP induces contraction, whereas VIP induces relaxation. Here, we have attempted to identify key residues responsible for their interactions with PACAP (PAC1) and VIP (VPAC) receptors in the guinea pig gallbladder. We synthesized PACAP-27/VIP hybrid peptides and compared their actions on isolated guinea pig gallbladder smooth muscle strips using isotonic transducers.

View Article and Find Full Text PDF

A novel dry peptide microarray system has been constructed that affords a practical solution for protein detection and analysis. This system is an array preparation and assay procedure under dry conditions that uses designed peptides as non-immobilized capture agents for the detection of proteins. The system has several advantages that include its portability and ease-of-use, as well as the fact that vaporization of sample solutions need not be considered.

View Article and Find Full Text PDF

Our previous study reported that an osteopontin-derived peptide SVVYGLR activates the adhesion, migration and tube formation abilities of endothelial cells in vitro. The present study investigated angiogenesis due to synthetic SVVYGLR and mutant peptides in vivo. Mutant peptides (n = 7) were synthesized by substituting alanine (A) for one of the 7 amino acids comprising SVVYGLR.

View Article and Find Full Text PDF

A practical high-throughput protein detection system is described, based on synthetic peptide arrays consisting of designed alpha-helical peptides, detected by fluorescence resonance energy transfer (FRET). Initially a model alpha-helical peptide known to interact with a structured protein, calmodulin, was selected to establish the strategy for high-throughput detection. In comparison to peptides with a single probe, a much higher FRET response has been observed with two fluorescent probes (7-diethylaminocoumarin-3-carboxylic acid and 5(6)-carboxy-fluorescein) at both termini of the synthetic peptides.

View Article and Find Full Text PDF