Origin Identification and Quantitative Analysis of Honeys by Nuclear Magnetic Resonance and Chemometric Techniques

The combination of H-1 NMR spectroscopy and multivariate statistical analysis has become a promising method for the discrimination of food origins. In this paper, this method has been successfully employed to analyze 70 Chinese honey samples from eight botanic origins, three geographical origins, and five production dates. Thirty-three components in honey samples were detected and identified from their H-1 NMR spectra, and 20 of them were accurately quantified by comparing their integral area with that of internal standards with relaxation time correction. Nontargeted principal component analysis (PCA) has been applied to distinguish the honeys from different botanical and geographical origins. The variations of components in the honeys, including saccharides and all kind of amino and organic carboxylic acids, confirmed their clustering according to their origins in PCA scores plots. Orthogonal partial least squares discriminant analysis (OPLS-DA) based on the NMR data for the different pairwise honey samples allows to identify the compositional variations contributed to geographical discrimination and storage time. Hence, NMR spectroscopy coupled with chemometric techniques offers an efficient tool for quality control of honey, and it could further serve to the classification, qualitative and quantitative control of other foods

The relations between metabolic variations and genetic evolution of different species

Metabonomics has been applied in many bio-related scientific fields. Nevertheless, some animal research works are shown to fail when they are extended to humans. Therefore, it is essential to figure out suitable animal modeling to mimic human metabolism so that animal findings can serve humans. In this study, two kinds of commonly selected body fluids, serum and urine, from humans and various experimental animals were characterized by integration of nuclear magnetic resonance (NMR) spectroscopy with multivariate statistical analysis to identify the interspecies metabolic differences and similarities at a baseline physiological status. Our results highlight that the dairy cow and pig may be an optimal choice for transportation and biodistribution studies of drugs and that the Kunming (KM) mouse model may be the most effective for excretion studies of drugs, whereas the Sprague-Dawley (SD) rat could be the most suitable candidate for animal modeling under overall considerations. The biochemical pathways analyses further provide an interconnection between genetic evolution and metabolic variations, where species evolution most strongly affects microbial biodiversity and, consequently, has effects on the species-specific biological substances of biosynthesis and corresponding biological activities. Knowledge of the metabolic effects from species difference will enable the construction of better models for disease diagnosis, drug metabolism, and toxicology research. (C) 2015 Elsevier Inc. All rights reserved.Metabonomics has been applied in many bio-related scientific fields. Nevertheless, some animal research works are shown to fail when they are extended to humans. Therefore, it is essential to figure out suitable animal modeling to mimic human metabolism so that animal findings can serve humans. In this study, two kinds of commonly selected body fluids, serum and urine, from humans and various experimental animals were characterized by integration of nuclear magnetic resonance (NMR) spectroscopy with multivariate statistical analysis to identify the interspecies metabolic differences and similarities at a baseline physiological status. Our results highlight that the dairy cow and pig may be an optimal choice for transportation and biodistribution studies of drugs and that the Kunming (KM) mouse model may be the most effective for excretion studies of drugs, whereas the Sprague-Dawley (SD) rat could be the most suitable candidate for animal modeling under overall considerations. The biochemical pathways analyses further provide an interconnection between genetic evolution and metabolic variations, where species evolution most strongly affects microbial biodiversity and, consequently, has effects on the species-specific biological substances of biosynthesis and corresponding biological activities. Knowledge of the metabolic effects from species difference will enable the construction of better models for disease diagnosis, drug metabolism, and toxicology research. (C) 2015 Elsevier Inc. All rights reserved

Track the Conformational Change of Unlabeled Yeast Cytochrome c in Cell Homogenate Using NMR

Cytochrome c (cyt c) is an important multifunctional protein. In mitochondria, it acts as a carrier for electron transporting. In cytoplasm, it may act as an apoptotic initiator to initiate the apoptotic process. Whether and how a complex cytoplasmic environment affects its conformation has not been confirmed yet. In this study, the conformational changes of wild type saccharomyces cerevisiae iso-1 cyt c in yeast cell homogenate were tracked by methyl-based nuclear magnetic resonance (NMR) technique. At least four different oxidative conformations and one reduced conformation of cyt c were identified in cell homogenate. And over time, the transitions among different conformations of cyt c were observed. The results indicate that the conformation of cyt c changes with environment, which may be closely related to resistance to oxidative stress

H-1 NMR-based metabolomics study on the physiological variations during the rat pregnancy process

In this study, NMR-based metabolomics in combination with multivariate pattern recognition technologies were employed to evaluate the physiological variations in the Wistar rats' plasma that are induced by pregnancy on the gestational days (GDs) 11, 14, 17 and 20. Untargeted metabolomics analysis revealed some possible mechanism of physiological effects for healthy pregnancies and showed a metabolic trajectory during pregnancy process. The levels of 24 metabolites were found to change significantly throughout pregnancy in maternal plasma. These metabolite changes involved in varied kinds of metabolic pathways including synthesis of biological substances, microbial metabolism in diverse environments, protein digestion and absorption, carbohydrate metabolism, digestion and absorption, mineral absorption, and ATP (Adenosine Triphosphate)-binding cassette transporters (ABC transporters). The substantial cores of all the metabolic pathways are promoting fetal growth and development and regulating maternal physiological state. This work showed relevant metabolic pathways perturbation in the maternal plasma due to normal pregnancy and provided the physical basis of time-dependent metabolic trajectory against which disease-related maternal physiological responses may be better understood in future studies. (C) 2016 Elsevier Ireland Ltd. All rights reserved

Amyloid-beta Deposition and Olfactory Dysfunction in an Alzheimer's Disease Model

Olfactory dysfunction is closely related to Alzheimer's disease (AD). Yet the mechanism behind this dysfunction remains largely unknown. To clarify the relationship between olfactory and memory deficits, we assessed behavioral and olfactory system pathology in A beta PP/PS1 transgenic mice using the olfactory threshold test, the Morris water maze, Western blotting, immunohistochemistry (IHC), and thioflavine-s staining. Western blotting revealed the following spatial-temporal deposition of amyloid-beta (A beta): appeared in the olfactory epithelium at 1-2 months old (mo); expanded to the olfactory bulb at 3-4 mo; expanded to the anterior olfactory nucleus, piriform cortex, entorhinal cortex, and hippocampus at 6-7 mo; and increased with age (9-10 mo) in the more central cortices. IHC staining showed similar results, but the appearance time points for the spotty signals in these brain regions were earlier due to the higher spatial resolution compared with Western blotting. The spread of A beta deposits from the olfactory epithelium to the olfactory bulb, the anterior olfactory nucleus, and piriform cotex (faint) at 3-4 mo correlated with the olfactory detection deficit found at the corresponding age; and the high level of depositions in the more central regions at 9-10 mo correlated with spatial memory deficit at the same age. We also found that a decline in the levels of olfactory marker protein, a marker of functioning olfactory sensory neuron, coincided with soluble A beta aggregates from a very early age in the olfactory epithelium, indicating early olfactory sensory neuron degeneration in the A beta PP/PS1 mouse as in AD patients. The current data suggest that the early deposition of soluble A beta aggregates in the olfactory system and the early deficit in olfactory dysfunction have the potential to serve as molecular markers for the early diagnosis of AD.Olfactory dysfunction is closely related to Alzheimer's disease (AD). Yet the mechanism behind this dysfunction remains largely unknown. To clarify the relationship between olfactory and memory deficits, we assessed behavioral and olfactory system pathology in A beta PP/PS1 transgenic mice using the olfactory threshold test, the Morris water maze, Western blotting, immunohistochemistry (IHC), and thioflavine-s staining. Western blotting revealed the following spatial-temporal deposition of amyloid-beta (A beta): appeared in the olfactory epithelium at 1-2 months old (mo); expanded to the olfactory bulb at 3-4 mo; expanded to the anterior olfactory nucleus, piriform cortex, entorhinal cortex, and hippocampus at 6-7 mo; and increased with age (9-10 mo) in the more central cortices. IHC staining showed similar results, but the appearance time points for the spotty signals in these brain regions were earlier due to the higher spatial resolution compared with Western blotting. The spread of A beta deposits from the olfactory epithelium to the olfactory bulb, the anterior olfactory nucleus, and piriform cotex (faint) at 3-4 mo correlated with the olfactory detection deficit found at the corresponding age; and the high level of depositions in the more central regions at 9-10 mo correlated with spatial memory deficit at the same age. We also found that a decline in the levels of olfactory marker protein, a marker of functioning olfactory sensory neuron, coincided with soluble A beta aggregates from a very early age in the olfactory epithelium, indicating early olfactory sensory neuron degeneration in the A beta PP/PS1 mouse as in AD patients. The current data suggest that the early deposition of soluble A beta aggregates in the olfactory system and the early deficit in olfactory dysfunction have the potential to serve as molecular markers for the early diagnosis of AD

Structures of Anabaena Calcium-binding Protein CcbP INSIGHTS INTO CA(2+) SIGNALING DURING HETEROCYST DIFFERENTIATION

Ca2+-binding proteins play pivotal roles in both eukaryotic and prokaryotic cells. CcbP from cyanobacterium Anabaena sp. strain PCC 7120 is a major Ca2+-binding protein involved in heterocyst differentiation, a process that forms specialized nitrogen-fixing cells. The three-dimensional structures of both Ca2+-free and Ca2+-bound forms of CcbP are essential for elucidating the Ca2+-signaling mechanism. However, CcbP shares low sequence identity with proteins of known structures, and its Ca2+-binding sites remain unknown. Here, we report the solution structures of CcbP in both Ca2+-free and Ca2+-bound forms determined by nuclear magnetic resonance spectroscopy. CcbP adopts an overall new fold and contains two Ca2+-binding sites with distinct Ca2+-binding abilities. Mutation of Asp(38) at the stronger Ca2+-binding site of CcbP abolished its ability to regulate heterocyst formation in vivo. Surprisingly, the beta-barrel subdomain of CcbP, which does not participate in Ca2+-binding, topologically resembles the Src homology 3 (SH3) domain and might act as a protein-protein interaction module. Our results provide the structural basis of the unique Ca2+ signaling mechanism during heterocyst differentiation