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The Sparse-Fur (Otcspf) and Abnormal Skin and Hair (Otcash) Mutations, Chromosome X
Published in John P. Sundberg, Handbook of Mouse Mutations with Skin and Hair Abnormalities, 2020
John P. Sundberg, Donald P. Doolittle
Ornithine transcarbamylase is a mitochondrial enzyme in the urea cycle that catalyzes the formation of citrulline from carbamoyl phosphate and ornithine.6 Mutant forms of this enzyme have been described in sparse-fur and in abnormal skin and hair mice.2,7 The enzymatic abnormality can be detected in the liver, duodenum, jejunum, and ileum.8 Mouse ornithine transcarbamylase is a trimer, similar to that in other species. The sparse-fur mutation does not affect the molecular weight of this enzyme. The affinity for ornithine and norvaline is decreased in mutant mice.9 Livers of hemizygous abnormal skin and hair mice synthesize two distinct ornithine transcarbamylase precursor polypeptides; one is normal in size, and the second is elongated. Both enzymes are processed by mitochondria, but only the one of normal size is assembled into the active trimer.10 The molecular lesion is a C to A transversion of the ornithine transcarbamylase gene in the sparse-fur mouse mutation that alters a histidine residue to an asparagine residue at amino acid 117.11 Correction of this enzymatic deficiency has been successful using transgenic approaches.12–16
The Discovery of the GSH Receptor in Hydra and Its Evolutionary Significance
Published in Christopher A. Shaw, Glutathione in the Nervous System, 2018
From these findings, it is apparent that neither the reducing nor the hydrogenbonding properties of the thiol group of cysteine are needed to activate the receptors. The size and hydrophobicity of the 2-position side chain, however, may play a role in affecting the activating properties of tripeptide analogs. For example, quantitative examination of the data summarized in Table 2 shows a corresponding loss in activation and binding potency with norvaline > α-amino-n-butyric acid > alanine > glycine. Within this latter series of tripeptides, the potency probably does not depend on size alone, but on the degree of lipophilicity and conformation flexibility inherent in the substituted groups. It is interesting that γ-glutamylglycylglycine did not activate, but instead was a weak antagonist. Hence, it is not simply the tripeptide structure that is required for activation. Possibly the substitution of glycine in 2 position affects the conformation of the tripeptide so it will not activate. Addition of a small side chain, such as an ethyl or a methyl, to that glycine might lead to a conformation of the tripeptide more compatible with the receptor.
Glutamate Dehydrogenase
Published in Elling Kvamme, Glutamine and Glutamate in Mammals, 1988
Ox liver glutamate dehydrogenase has been shown to be capable of catalyzing the oxidation of glutamate analogues such as l-homocysteine sulfinic acid90 and a number of monocar-boxylic amino acids. Of the latter, l-norvaline has been shown to be the best alternative substrate with a rate of oxidation 17% of that of glutamate at pH 9.0.91 The rates of oxidation of the monocarboxylic amino acids leucine, valine, norleucine, isoleucine, methionine, alanine, and ct-aminobutyrate were all less than 3% of the initial rate of glutamate oxidation under these conditions. The optimal pH values for the oxidation of monocarboxylic α-amino acids have been shown to be rather higher than that for the oxidation of glutamate.91,92
Tao-Hong-Si-Wu decoction improves depressive symptoms in model rats via amelioration of BDNF-CREB-arginase I axis disorders
Published in Pharmaceutical Biology, 2022
Xiaoping Zhang, Zeng Li, Chuanpu Shen, Jinzhi He, Longfei Wang, Lei Di, Bin Rui, Ning Li, Zhicheng Liu
HPLC-grade methanol, isopropanol, acetonitrile, methoxamine salt, pyridine, pentobarbital and N-paraffin mix used for calculating retention index were purchased from J&K Scientific Ltd. (Shanghai, China). HPLC-grade N-methyl-N-trimethylsilyltrifluoroacetamide and the standard substances including l-norvaline, l-lysine, l-tyrosine, l-phenylalanine, l-serine, l-valine, l-glutamic acid, l-alanine, l-proline, l-ornithine, d-glucose, sucrose, urea, lactic acid and fluoxetine were purchased from Sigma-Aldrich Ltd. (Shanghai, China). The standard products of the six herbs included in TSD were bought from Desite Company (Chengdu, China). Ultrapure water was prepared by the Milli-Q system (Merck, Darmstadt, Germany).
Activation of ectopic olfactory receptor 544 induces GLP-1 secretion and regulates gut inflammation
Published in Gut Microbes, 2021
Chunyan Wu, Mi-Young Jeong, Jung Yeon Kim, Giljae Lee, Ji-Sun Kim, Yu Eun Cheong, Hyena Kang, Chung Hwan Cho, Jimin Kim, Min Kyung Park, You Kyoung Shin, Kyoung Heon Kim, Geun Hee Seol, Seung Hoi Koo, GwangPyo Ko, Sung-Joon Lee
Principal component analysis, including key organic acids and amino acids revealed that metabolite profile of WT and Olfr544-KO mice were localized closely, indicating that the fecal metabolite profiles of WT and Olfr544-KO mice are comparable (Supplementary Figure 6). To examine the changes in metabolism in the gut environment by AzA, MetaMapp and the metabolite sets enrichment analysis (MSEA) were performed in WT and Olfr544-KO mice orally administered with AzA (Figure 5(a,b)). Notably, results suggested that AzA administration significantly increased the levels of norvaline, succinate, trehalose, and O-phosphorylethanolamine in WT mice, but not in Olfr544-KO mice (Figure 5(a)). Norvaline was correlated with significantly increased the levels of glutamate and oxoproline, the intermediates of glutathione metabolism.22 AzA also elevated the levels of 6-phosphogluconate, a key metabolite in the pentose phosphate pathway, which supplies NADPH toanabolism.23 Succinate is known to be secreted by B. acidofaciens. Trehalose is a stress-resistance compound that is synthesized by microorganisms in a stressed environment, such as under oxidative stress and heat shock.24O-phosphorylethanolamine is a metabolite in phospholipid synthesis for cell growth. These findings suggest that AzA affects survival and the proliferation of certain gut microorganisms with increased trehalose, phospholipid, succinate, and glutathione synthesis. Induced glutathione and NADPH synthesis may enhance antioxidative capacity in gut.
Branched-chain amino acids are associated with metabolic parameters in bipolar disorder
Published in The World Journal of Biological Psychiatry, 2019
Frederike T. Fellendorf, Martina Platzer, Rene Pilz, Alexandra Rieger, Hans-Peter Kapfhammer, Harald Mangge, Nina Dalkner, Sieglinde Zelzer, Andreas Meinitzer, Armin Birner, Susanne A. Bengesser, Robert Queissner, Carlo Hamm, Riccarda Hartleb, Eva Z. Reininghaus
Cholesterol, lipoproteins and triglycerides were measured from fasting blood by enzymatic photometric methods. Plasma insulin was measured by ELISA and glucose by the hexokinase method. The homeostatic model assessment index-insulin resistance (HOMA-IR) was calculated, as defined by Matthews et al. (1985). BCAA levels were measure in peripheral blood serum and assessed by use of a reversed phase high-performance liquid chromatography method (Schwarz et al. 2005). In brief, after precipitation of proteins with perchloric acid and neutralisation with sodium carbonate, the extracted AAs were derivatized with o-phtalaldehyde and separated on a reversed-phase column with gradient elution. Quantification was performed with ratios of fluorescence signals to the internal standard norvaline in comparison to the appropriated calibration curves. Intra- and inter-assay coefficients of varation at different concentrations were all below 10%.