Melt spinnabilities of thermoplastic paramylon mixed esters.

The low thermoplasticities of polysaccharide esters make them unsuitable for melt spinning. In this study, we aimed to overcome this problem by mixed esterification of paramylon, a euglenoid β-1,3-glucan with short- and medium-chain acyl groups, as melt-spinnable materials. Thermal analyses revealed that all the synthesized paramylon mixed esters exhibited glass transition temperatures greater than 100 °C; some of them showed large differences between the melting and 5%-weight-loss temperatures (5s) and are extrudable through a spinneret at a temperature ~100 °C below 5, rendering them potential candidates for the production of melt-spun filaments.

Changes in brain metabolites related to stress resilience: Metabolomic analysis of the hippocampus in a rat model of depression.

The ability to cope successfully with stress is known as 'resilience', and those with resilience are not prone to developing depression. One preclinical animal model for depression is the chronic mild stress (CMS) model. There are CMS-resilient (do not manifest anhedonia) and CMS-susceptible (manifest anhedonia) rats.

High-Resolution Magic-Angle Spinning-H-NMR Spectroscopy-Based Metabolic Profiling of Hippocampal Tissue in Rats with Depression-Like Symptoms.

Depressive disorders cause large socioeconomic effects influencing not only the patients themselves but also their family and broader community as well. To better understand the physiologic factors underlying depression, in this study, we performed metabolomics analysis, an omics technique that comprehensively analyzes small molecule metabolites in biological samples. Specifically, we utilized high-resolution magic-angle spinning-H-NMR (HRMAS-H-NMR) spectroscopy to comprehensively analyze the changes in metabolites in the hippocampal tissue of rats exposed to chronic stress (CS) via multi-step principal component analysis (multi-step PCA).

Short-term feeding at the wrong time is sufficient to desynchronize peripheral clocks and induce obesity with hyperphagia, physical inactivity and metabolic disorders in mice.

Background: The circadian clock regulates various physiological and behavioral rhythms such as feeding and locomotor activity. Feeding at unusual times of the day (inactive phase) is thought to be associated with obesity and metabolic disorders in experimental animals and in humans.

Objective: The present study aimed to determine the underlying mechanisms through which time-of-day-dependent feeding influences metabolic homeostasis.

A NMR-based, non-targeted multistep metabolic profiling revealed L-rhamnitol as a metabolite that characterised apples from different geographic origins.

This study utilises (1)H NMR-based metabolic profiling to characterise apples of five cultivars grown either in Japan (Fuji, Orin, and Jonagold) or New Zealand (Fuji, Jazz, and Envy). Principal component analysis (PCA) showed a clear separation between the Fuji-Orin-Jonagold class and the Jazz-Envy class, primarily corresponding to the differences in sugar signals, such as sucrose, glucose, and fructose. Multistep PCA removed the influence of dominant sugars and highlighted minor metabolites such as aspartic acid, 2-methylmalate, and an unidentified compound.

Disruption of behavioral circadian rhythms induced by psychophysiological stress affects plasma free amino acid profiles without affecting peripheral clock gene expression in mice.

Disordered circadian rhythms are associated with various psychiatric conditions and metabolic diseases. We recently established a mouse model of a psychophysiological stress-induced chronic sleep disorder (CSD) characterized by reduced amplitude of circadian wheel-running activity and sleep-wake cycles, sleep fragmentation and hyperphagia. Here, we evaluate day-night fluctuations in plasma concentrations of free amino acids (FAA), appetite hormones and prolactin as well as the hepatic expression of circadian clock-related genes in mice with CSD (CSD mice).

Quantification of molecules in (1)H-NMR metabolomics with formate as a concentration standard.

Quantitative analysis of metabolites is important in (1)H-nuclear magnetic resonance (NMR)-based metabolomics of plasma. Human plasma contains a high density of proteins which heavily adsorb the commonly-used standard compound of sodium 3-(trimethylsilyl) propionate 2, 2, 3, 3-d(4) (TSP). We have evaluated calcium formate as an alternative standard in 1D single-pulse (1)H-NMR spectra to quantify plasma metabolites.

Developmental delineation of metabolic-patterns of neonatal mice by using NMR-metabolic profiling on highly-diluted urine.

Blood circulation and the route of nutritional supply both change dramatically in the immediate neonatal period. These systemic shifts lead to adjustment of metabolic patterns in the neonate, with alterations in the spectrum of metabolites in body fluids. We have investigated whether (1)H-NMR-based metabolic profiling (NMR-MP) with principal component analysis (PCA) can be used to evaluate metabolite profiles in highly-diluted samples of individual neonatal mouse urine.

NMR metabolic profiling combined with two-step principal component analysis for toxin-induced diabetes model rat using urine.

Nuclear magnetic resonance-based metabolic profiling (NMR-MP) was applied to evaluate disorder model animals using urine. Diabetic nephropathy was established in this experiment by administering streptozotocin to Wistar rats, which immediately developed diabetes after toxin-treatment and then gradually produced albumin-containing urine (albuminuria). Urine samples were collected for the first 4 weeks after toxin treatment.

Copper (II) modulates in vitro aggregation of a tau peptide.

Copper (II) has been implicated in the pathology of Alzheimer's disease (AD) for the impaired homeostatic mechanism found in the brains of AD patients. Here we studied the binding properties of Cu(II) with the first microtubule-binding repeat, encompassing residues 256-273 of the human tau441 sequence. Additionally, the effect of Cu(II) on the assembly of this repeat was also investigated.

Functional analysis of Arabidopsis thaliana RHM2/MUM4, a multidomain protein involved in UDP-D-glucose to UDP-L-rhamnose conversion.

UDP-L-rhamnose is required for the biosynthesis of cell wall rhamnogalacturonan-I, rhamnogalacturonan-II, and natural compounds in plants. It has been suggested that the RHM2/MUM4 gene is involved in conversion of UDP-D-glucose to UDP-L-rhamnose on the basis of its effect on rhamnogalacturonan-I-directed development in Arabidopsis thaliana. RHM2/MUM4-related genes, RHM1 and RHM3, can be found in the A.

Pattern recognition analysis for classification of hypertensive model rats and diurnal variation using 1H-NMR spectroscopy of urine.

Urine samples were collected during the daytime and nighttime from spontaneously hypertensive model rats and normal rats without dosing. The 1H NMR spectra were measured for their urine samples, and analyzed by a pattern recognition method, known as Principal Component Analysis (PCA) and Soft Independent Modeling of Class Analogy (SIMCA). The separation of urinary data due to the diurnal variation (daytime and nighttime) and also to the difference between the two strains of rat was achieved in the PCA score plot.

Low-barrier hydrogen bond between phosphate and the amide group in phosphopeptide.

As the conversion between the monoionic (1) and diionic (2) form of the phosphate occurs, the phosphorylated peptides or proteins can not only cause the formation of a hydrogen bond between the phosphate group and the amide group but also change the strength of the hydrogen bond to form low-barrier hydrogen bonds (LBHBs). This reversible protonation of the phosphate group, which changes both the electrostatic properties of the phosphate group and the strength of the hydrogen bond, provides a possible mechanism in regulating protein function.

Ab initio fragment molecular orbital (FMO) method applied to analysis of the ligand-protein interaction in a pheromone-binding protein.

Full quantum computation of the electronic state of proteins has recently become possible by the advent of the ab initio fragment molecular orbital (FMO) method. We applied this method to the analysis of the interaction between the Bombyx mori pheromone-binding protein and its ligand, bombykol. The protein-ligand interaction of this molecular complex was minutely analyzed by the FMO method, and the analysis revealed several important interactions between the ligand and amino acid residues.

Copper binding properties of a tau peptide associated with Alzheimer's disease studied by CD, NMR, and MALDI-TOF MS.

We have previously reported the copper binding properties of R3 peptide (residues 318-335: VTSKCGSLGNIHHKPGGG, according to the longest tau protein) derived from the third repeat microtubule-binding domain of water-soluble tau protein. In this work, we have investigated copper binding properties of R2 peptide (residues 287-304: VQSKCGSKDNIKHVPGGG) derived from the second repeat region of tau protein. Similar to R3 peptide, R2 peptide also plays an important role in the formation of neurofibrillary tangles (NFTs) which is one of the two main biological characteristics of Alzheimer's disease (AD).

Binding of copper (II) ion to an Alzheimer's tau peptide as revealed by MALDI-TOF MS, CD, and NMR.

The tau protein plays an important role in some neurodegenerative diseases including Alzheimer's disease (AD). Neurofibrillary tangles (NFTs), a biological marker for AD, are aggregates of bundles of paired helical filaments (PHFs). In general, the alpha-sheet structure favors aberrant protein aggregates.

Quantitation of de novo localized (15)N-labeled lipoproteins and membrane proteins having one and two transmembrane segments in a Bacillus subtilis secA temperature-sensitive mutant using 2D-PAGE and MALDI-TOF MS.

We developed a means of quantifying proteins that have just localized in the cytoplasmic membrane using 15N-whole cell labeling together with 2D-PAGE and MALDI-TOF MS. The localization of 18 among 20 proteins consisting of 8 lipoproteins, 11 integral membrane proteins having one or two transmembrane segments and one secretory protein in the membrane fractions of Bacillus subtilis, was inhibited by the absence of SecA in a temperature-sensitive mutant. The time course of inhibition indicated that SecA participates in the localization of those proteins through immediately dependent, delayed dependent, and independent ways.

Application of ultra-high magnetic field for saccharide molecules: 1H NMR spectra of 6-O-alpha-D-glucopyranosyl-cyclomaltoheptaose and -cyclomaltohexaose.

1H NMR spectra of G1-alpha-CD and G1-beta-CD were recorded using a spectrometer equipped with a 21.6 T magnet. An ultra-high magnetic field was effective for detecting 1H NMR signals with a small difference in chemical shifts.

1H NMR spectra of branched-chain cyclomaltohexaoses (alpha-cyclodextrins).

The 1H NMR spectra of seven branched alpha-cyclodextrins (alpha-CDs) were observed and analyzed in detail. They were compared with spectra of alpha-CD and amylose. Although these branched alpha-CDs consist only of alpha-D-glucose with the same alpha-(1-->4) O-glucosyl binding, aside from one exception, differences in chemical shifts of corresponding signals were significantly large.

Profiling and comprehensive expression analysis of ABC transporter solute-binding proteins of Bacillus subtilis membrane based on a proteomic approach.

We analyzed ABC transporter solute-binding proteins (SBPs) of the Bacillus subtilis membrane using a proteomic approach. We prepared a washed cell membrane fraction that was insoluble in 134 mM nondetergent sulfobetaine and then extracted proteins using mixtures of detergents in a stepwise manner. The membrane proteins were resolved by three two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) or two one-dimensional (1-D) PAGE procedures, electroblotted, and digested in the presence of 5% or 80% acetonitrile.

Detection of specific noncovalent interaction of peptide with DNA by MALDI-TOF.

Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry was used to obtain spectra of peptide-DNA complexes formed by basic domain (BD15) of c-Fos protein and DNA AP-1 site (5'-TGAGTCA-3'). The noncovalent interaction between single stranded DNA and BD15 was observed and confirmed to be an ionic one between the negatively charged sugar-phosphate backbone of DNA and positively charged side chains of Arg- and lys-rich peptides as demonstrated by Vertes and coworkers and Woods and coworkers. But the specific noncovalent interaction between DNA AP-1 site and the dimer of BD15 was firstly detected in this paper.

Proteomic analysis of acrylamide gel separated proteins immobilized on polyvinylidene difluoride membranes following proteolytic digestion in the presence of 80% acetonitrile.

Two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) combined with mass spectrometry (MS) is a highly accurate and sensitive means of identifying proteins. We have developed a novel method for digesting proteins on polyvinylidene difluoride (PVDF) membranes for subsequent matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) MS analysis. After Tricine sodium dodecyl sulfate (SDS)-PAGE, separated proteins were electroblotted onto PVDF membranes in a semidry discontinuous buffer system, visualized by staining with Coomassie Blue, excised, digested with trypsin or lysC in 80% acetonitrile, and then analyzed by MALDI-TOF MS.