Biomedical subjects

Toshiyuki Moriuchi

Publications and source records attributed to Toshiyuki Moriuchi.

7 recordsLinked to original sources

PubMed2006

Induction of gamma-turn-like structure in ferrocene bearing dipeptide chains via conformational control.

[structure: see text] A combination of the ferrocene scaffold as a central reverse-turn unit with the dipeptide chains (-L-Pro-L-Ala-NHPy) was demonstrated to induce both inverse gamma-turn-like and antiparallel beta-sheet-like structures. Only the antiparallel beta-sheet-like structure was formed in the ferrocene bearing the heterochiral dipeptide chains (-L-Pro-D-Ala-NHPy), in which highly organized self-assembly was achieved through a network of intermolecular hydrogen bonds.

Dipeptides↗

PubMed2006

The prevalence of human papillomavirus genotypes in penile cancers from northern Thailand.

The highest frequency of penile cancer occurs in Asia, Africa, and Latin America, and there have been a few reports concerning the association of penile cancer with human papillomavirus (HPV) infection in these areas. The objective of this study was to determine the relation between penile cancer and the prevalence of HPV genotypes in northern Thailand. Eighty-eight specimens of penile tissue (65 malignant, 1 pre-malignant, and 22 benign cases) were examined to determine the association of HPV infection. An in situ hybridization (ISH) method was used to detect and localize HPV-DNA. Sensitive HPV polymerase chain reaction (PCR) procedure was used for detection of HPV-DNA, and DNA sequencing was used to identify the HPV genotype. HPV-DNA was detected in 53.8% and 81.5% of cases of penile cancer, using ISH and PCR, respectively. The high-risk HPV-16, most commonly associated with penile cancer in previous reports, was found in only one case in this study. The most prevalent genotype was the high-risk HPV-18, found in 55.4% of the cases (32.3% single and 23.1% multiple infection) followed by the low-risk HPV-6, found in 43.1% of the cases (24.6% single and 18.5% multiple infection). In this study, penile cancer was found to be highly correlated with HPV-DNA. Specifically, infection with both the low-risk HPV-6 and the high-risk HPV-18 is the characteristic prevalence of HPV genotypes in penile cancer in this area.

Adult↗

PubMed2005

Chirality organization of ferrocenes bearing dipeptide chains of heterochiral sequence.

[structures: see text] The symmetrical introduction of two dipeptide chains of heterochiral sequence (-L-Ala-D-Pro-NHPy) into the ferrocene scaffold as a central reverse-turn unit was demonstrated to induce both antiparallel beta-sheet-like and type II beta-turn-like structures simultaneously, affording the chirality-organized structure. The ferrocene bearing only one dipeptide chain (-L-Ala-D-Pro-NHPy) exhibited a left-handed helically ordered molecular assembly through a network of intermolecular hydrogen bonds instead of intramolecular hydrogen bonds.

Alanine↗

PubMed2004

Highly ordered structures of peptides by using molecular scaffolds.

Protein secondary structures such as alpha-helices, beta-sheets, and beta-turns are important in inducing the three-dimensional structure and biological activity of proteins. Designing secondary structure mimics composed of short peptides has attracted much attention not only to gain fundamental insight into the factors affecting protein folding but also to develop pharmacologically useful compounds, artificial receptors, asymmetric catalysts, and new materials. In this tutorial review, we focus on molecular scaffolds employed to induce beta-sheet-like structure in attached peptide chains, thereby creating highly ordered molecular structures, and discuss the versatility of these molecular scaffolds to regulate the attached peptide strands in the appropriate dimensions.

Ferrous Compounds↗

PubMed2003

Chirality-organized ferrocene receptor bearing podand dipeptide chains (-L-Ala-L-Pro-NHPyMe) for the selective recognition of dicarboxylic acids.

[structure: see text] The ferrocene receptor bearing the podand dipeptide chains (-l-Ala-l-Pro-NHPyMe) was found to provide a chirality-organized binding site through two intramolecular interchain hydrogen bonds between CO (Ala) and NH (another Ala) of each podand dipeptide chain. The size-selective and chiral recognition of dicarboxylic acids was achieved by multipoint hydrogen bonds of the binding site.

Dipeptides↗

PubMed2002

Self-assembly of dipeptidyl ureas: a new class of hydrogen-bonded molecular duplexes.

The dipeptidyl urea 1 composed of two dipeptide chains bearing the C-terminal pyridyl moiety (-L-Ala-L-Pro-NHPy) was prepared. Two molecules of 1 are revealed to be held together by six intermolecular hydrogen bonds to form a hydrogen-bonded duplex by the single-crystal X-ray structure determination. Proton magnetic resonance nuclear Overhauser effect (NOE) study indicates the hydrogen-bonded duplex even in solution. Furthermore, a shuttle-like molecular dynamics based on recombination of the hydrogen bonds was observed. The dipeptidyl urea composed of two dipeptide chains bearing the C-terminal pyrenyl moiety (-L-Ala-L-Pro-NHCH(2)Pyr) exhibited both monomer and eximer emissions in the fluorescence spectra, supporting the formation of a duplex. A combination of the C-terminal amide NH function in each side and the designed sequence of hydrogen-bonding sites are considered to be a crucial factor for the duplex formation.

Dipeptides↗

PubMed2002

Architectural formation of a conjugated bimetallic Pd(II) complex via oxidative complexation and a tetracyclic Pd(II) complex via self-assembling complexation.

The conjugated homobimetallic palladium(II) complex [(L1)Pd(qd)Pd(L1)] (qd = quinonediimine) was obtained in a one-pot reaction by the in-situ oxidative complexation of 1,4-phenylenediamine with the palladium(II) complex [(L1)Pd(MeCN)] (H2L1 = N,N'-bis(2-phenylethyl)-2,6-pyridinedicarboxamide) while in the absence of an additional ligand [(L1)Pd(MeCN)] was converted to the amide-bridged macrocyclic tetramer [Pd(L1)]4.

Journal Article↗