Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.25.1 (proteasome)
28,817 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The protease-catalyzed, kinetically controlled synthesis of a precursor dipeptide of thymopentin(TP-5), Z-Arg-Lys-NH2 in organic solvents was studied. Z-Arg-OMe was used as the acyl donor and Lys-NH2 was used as the nucleophile. An industrial alkaline protease alcalase and trypsin were used to catalyze the synthesis of the target dipeptide in water-organic cosolvent systems. The conditions of the synthesis reaction were optimized by examining the effects of several factors, including organic solvents, water content, temperature, pH, and reaction time on the yield of Z-Arg-Lys-NH2. The optimum conditions using alcalase as the catalyst are pH 10.0, 35 degrees C, in acetonitrile/DMF/Na2CO3-NaHCO3 buffer system (80:10:10, V/V), 6 h, with the dipeptide yield of 71.1%. Compared with alcalase, the optimum conditions for trypsin are pH 8.0, 35 degrees C, in ethanol/Tris-HCl buffer system (80:20, V/V), 4 h, with the dipeptide yield of 76.1%.
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PMID:Synthesis of a precursor dipeptide of thymopentin in organic solvents by an enzymatic method. 1832 Apr 67

Two experiments with growing pigs were conducted to determine the effects of dietary P and Ca level, phytase supplementation, and ileal pectin infusion on ileal and fecal P and Ca balance, chemical composition of fecal mixed bacterial mass (MBM), and bacterial metabolic activity. Pigs (initial BW = 30 kg) were fitted with simple T-cannulas at the distal ileum. They were fed a low-P corn-soybean meal control diet (3 g of P/kg) or the control diet supplemented with monocalcium phosphate (MCP; 7 g of P/kg; Exp. 1) or 1,000 FTU phytase/kg (Exp. 2). The daily infusion treatments consisted of 60 g of pectin dissolved in 1.8 L of demineralized water or 1.8 L of demineralized water as the control infusion, infused via the ileal cannula. In each experiment, 8 barrows were assigned to 4 dietary treatments according to a double, incomplete 4 x 2 Latin square. The dietary treatments in Exp. 1 were the control (Con-) diet with water infusion; the control (Con+) diet with pectin infusion; the MCP diet with water infusion; and the MCP diet with pectin infusion. In Exp. 2, the pigs received the same Con- and Con+ treatments as in Exp. 1 and, in addition, the phytase-supplemented diet in combination with water or pectin infusion. After a 15-d adaptation period, feces were collected for 5 d followed by ileal digesta collection for 24 h. In Exp. 1, supplemental MCP increased (P </= 0.003) ileal and fecal P and Ca recovery as well as P and Ca content of the MBM. Pectin infusion increased the N content of the MBM (P = 0.054) and polygalacturonase activity (P = 0.032) in feces. In addition, pectin decreased (P = 0.049) ileal and tended (P < 0. 079) to increase fecal VFA concentrations. In Exp. 2, phytase decreased ileal and fecal P recovery (P < 0.001) and the P content of the MBM (P = 0.045), whereas the N content of the MBM (P = 0.094) and fecal cellulase activity (P = 0.089) tended to decrease. Similarly, pectin infusion decreased (P = 0.036) fecal cellulase activity but increased (P < 0.001) polygalacturonase activity. In conclusion, these data indicate that bacterial P and Ca assimilation and metabolic activity depend on P and Ca availability in the large intestine and on the availability of fermentable substrate, such as pectin. Thus, increasing dietary P and Ca levels increases bacterial P and Ca assimilation due to greater intestinal P and Ca availability, whereas decreasing intestinal P availability for bacteria through phytase addition to low-P diets reduces bacterial P incorporation and seems to decrease bacterial activity.
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PMID:The effect of dietary phosphorus and calcium level, phytase supplementation, and ileal infusion of pectin on the chemical composition and carbohydrase activity of fecal bacteria and the level of microbial metabolites in the gastrointestinal tract of pigs. 1834 12

Atrazine (ATRA) is the most commonly applied herbicide in the United States and is frequently detected in drinking water at significant levels. After oral exposure, ATRA metabolism yields diaminochlorotriazine (DACT), an electrophilic molecule that has been shown to form covalent protein adducts. This research was designed to identify ATRA-induced protein adducts formed in the pituitary gland of ATRA-exposed rats and in DACT-exposed LbetaT2 rat pituitary cells. Immunohistochemistry showed diffuse cytoplasmic and nuclear staining in both pituitary sections and LbetaT2 cells indicating the formation of DACT protein adducts. Protein targets from both rat pituitaries and LbetaT2 cell culture were identified following two-dimensional electrophoresis (2DE), immunodetection, and matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis. Western blots from both exposed rats and LbetaT2 cells revealed over 30 DACT-modified spots that were not present in control animals. Protein spots were matched to concurrently run 2DE gels stained with Sypro Ruby, excised, and in-gel-digested with trypsin. Mass spectrometry analysis of digest peptides resulted in the identification of 19 spots and 8 unique proteins in the rats and 21 spots and 19 unique proteins in LbetaT2 cells. The identified proteins present in both sample types included proteasome activator complex subunit 1, ubiquitin carboxyl-terminal hydrolase isozyme L1, tropomyosin, ERp57, and RNA-binding proteins. Each of these proteins contains active-site or solvent-exposed cysteine residues, making them viable targets for covalent modification by DACT.
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PMID:Proteomic analysis of diaminochlorotriazine adducts in wistar rat pituitary glands and LbetaT2 rat pituitary cells. 1837 Apr 13

The DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN2A (DREB2A) transcription factor controls water deficit-inducible gene expression and requires posttranslational modification for its activation. The activation mechanism is not well understood; however, the stability of this protein in the nucleus was recently found to be important for its activation. Here, we report the isolation of Arabidopsis thaliana DREB2A-INTERACTING PROTEIN1 (DRIP1) and DRIP2, C3HC4 RING domain-containing proteins that interact with the DREB2A protein in the nucleus. An in vitro ubiquitination assay showed that they function as E3 ubiquitin ligases and are capable of mediating DREB2A ubiquitination. Overexpression of DRIP1 in Arabidopsis delayed the expression of DREB2A-regulated drought-responsive genes. Drought-inducible gene expression was slightly enhanced in the single T-DNA mutants of drip1-1 and drip2-1. By contrast, significantly enhanced gene expression was revealed in the drip1 drip2 double mutant under dehydration stress. Collectively, these data imply that DRIP1 and DRIP2 function negatively in the response of plants to drought stress. Moreover, overexpression of full-length DREB2A protein was more stable in drip1-1 than in the wild-type background. These results suggest that DRIP1 and DRIP2 act as novel negative regulators in drought-responsive gene expression by targeting DREB2A to 26S proteasome proteolysis.
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PMID:Arabidopsis DREB2A-interacting proteins function as RING E3 ligases and negatively regulate plant drought stress-responsive gene expression. 1855 97

Jatropha curcas is a tropical plant widely distributed in arid areas. The seeds contain about 55% of oil, which is mainly used for the production of soap as a fuel and after transesterification as biodiesel. Various methods for recovering of oil from the seeds, including extraction with organic solvents and water, have been investigated. Compared to hexane extraction (98%) the oil extraction using water only yielded 38% of the total oil content of the seeds. Using several cell wall degrading enzymes during aqueous extraction a maximum yield of 86% was obtained. The influence of cellulolytic, hemicellulolytic enzymes, as well as proteases was studied. The experiments were carried out at different pH-values and temperatures to find out the optimum for oil recovering using enzymes. , Surprisingly, the best results (86%) were obtained using an alkaline protease. Combinations of proteases with hemicellulases and/or cellulases did not further increase the extraction yield. The enzyme-supported aqueous extraction offers a nontoxic alternative to common extraction methods using organic solvents with reasonable yields.
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PMID:Enzyme-supported oil extraction from Jatropha curcas seeds. 1857 2

The formation of long-term memory requires protein synthesis, particularly during initial memory consolidation. This process also seems to be dependant upon protein degradation, particularly degradation by the ubiquitin-proteasome system. The aim of this study was to investigate the temporal requirement of protein synthesis and degradation during the initial consolidation of allocentric spatial learning. As memory returns to a labile state during reactivation, we also focus on the role of protein synthesis and degradation during memory reconsolidation of this spatial learning. Male CD1 mice were submitted to massed training in the spatial version of the Morris water maze. At various time intervals after initial acquisition or after a reactivation trial taking place 24 h after acquisition, mice received an injection of either the protein synthesis inhibitor anisomycin or the protein degradation inhibitor lactacystin. This injection was performed into the hippocampal CA3 region, which is specifically implicated in the processing of spatial information. Results show that, in the CA3 hippocampal region, consolidation of an allocentric spatial learning task requires two waves of protein synthesis taking place immediately and 4 h after acquisition, whereas reconsolidation requires only the first wave. However, for protein degradation, both consolidation and reconsolidation require only one wave, taking place immediately after acquisition or reactivation, respectively. These findings suggest that protein degradation is a key step for memory reconsolidation, as for consolidation. Moreover, as protein synthesis-dependent reconsolidation occurred faster than consolidation, reconsolidation did not consist of a simple repetition of the initial consolidation.
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PMID:Protein degradation, as with protein synthesis, is required during not only long-term spatial memory consolidation but also reconsolidation. 1858 39

A variety of enzymes have been found to acylate sucrose in anhydrous pyridine. The enzymic reaction is highly selective; with trifluoroethylbutyrate as ester donor, enzyme-catalyzed transesterification of sucrose yielded sucrose 1'-butyrate and sucrose 6, 1'-dibutyrate. No sucrose-tributyrates were formed. Using a similar technique, a long-chain linear sucrose polyester has been prepared using Proleather, an alkaline protease from a Bacillus sp. This protease catalyzes the esterification of sucrose with bis(2, 2, 2-trifluoroethyladipate) in a 1:1 ratio to yield a sucrose-containing polyester with M(w) = 2100 and M(n) = 1600 for a polydispersity of 1. 31. Polymers with molecular weights in excess of 13, 000 have been prepared by this enzymic approach, indicating that molecules containing over 30 sucrose units have been produced. The polyester is extremely water soluble and soluble in polar organic solvents. As with the sucrose dibutyrate, the polyester has ester linkages at the C6 and C1' positions on the sucrose. The polyester can be depolymerized using Proleather in aqueous buffer, pH7. After 9 days in aqueous buffer, Proleather catalyzed the breakdown of the polyester to an M(w) of ca. 900. This sucrose-containing polyester may have applications as a water-absorbent, biodegradable plastic for use as diapers and hygienic products, water-treatment chemicals, and components of drug delivery systems.
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PMID:Enzymatic synthesis of a sucrose-containing linear polyester in nearly anhydrous organic media. 1860 Jun 55

Adjustment of Na+ balance in extracellular fluids is achieved by regulated Na+ transport involving the amiloride-sensitive epithelial Na+ channel (ENaC) in the distal nephron. In this context, ENaC is controlled by a number of hormones, including vasopressin, which promotes rapid translocation of water and Na+ channels to the plasma membrane and long-term effects on transcription of vasopressin-induced and -reduced transcripts. We have identified a mRNA encoding the deubiquitylating enzyme ubiquitin-specific protease 10 (Usp10), whose expression is increased by vasopressin at both the mRNA and the protein level. Coexpression of Usp10 in ENaC-transfected HEK-293 cells causes a more than fivefold increase in amiloride-sensitive Na+ currents, as measured by whole cell patch clamping. This is accompanied by a three- to fourfold increase in surface expression of alpha- and gamma-ENaC, as shown by cell surface biotinylation experiments. Although ENaC is well known to be regulated by its direct ubiquitylation, Usp10 does not affect the ubiquitylation level of ENaC, suggesting an indirect effect. A two-hybrid screen identified sorting nexin 3 (SNX3) as a novel substrate of Usp10. We show that it is a ubiquitylated protein that is degraded by the proteasome; interaction with Usp10 leads to its deubiquitylation and stabilization. When coexpressed with ENaC, SNX3 increases the channel's cell surface expression, similarly to Usp10. In mCCD(cl1) cells, vasopressin increases SNX3 protein but not mRNA, supporting the idea that the vasopressin-induced Usp10 deubiquitylates and stabilizes endogenous SNX3 and consequently promotes cell surface expression of ENaC.
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PMID:Vasopressin-inducible ubiquitin-specific protease 10 increases ENaC cell surface expression by deubiquitylating and stabilizing sorting nexin 3. 1866 80

Ubiquitination is involved in diverse cellular processes in higher plants. In this report, we describe Arabidopsis thaliana PUB22 and PUB23, two homologous U-box-containing E3 ubiquitin (Ub) ligases. The PUB22 and PUB23 genes were rapidly and coordinately induced by abiotic stresses but not by abscisic acid. PUB22- and PUB23-overexpressing transgenic plants were hypersensitive to drought stress. By contrast, loss-of-function pub22 and pub23 mutant plants were significantly more drought-tolerant, and a pub22 pub23 double mutant displayed even greater drought tolerance. These results indicate that PUB22 and PUB23 function as negative regulators in the water stress response. Yeast two-hybrid, in vitro pull-down, and in vivo coimmunoprecipitation experiments revealed that PUB22 and PUB23 physically interacted with RPN12a, a subunit of the 19S regulatory particle (RP) in the 26S proteasome. Bacterially expressed RPN12a was effectively ubiquitinated in a PUB-dependent fashion. RPN12a was highly ubiquitinated in 35S:PUB22 plants, but not in pub22 pub23 double mutant plants, consistent with RPN12a being a substrate of PUB22 and PUB23 in vivo. In water-stressed wild-type and PUB-overexpressing plants, a significant amount of RPN12a was dissociated from the 19S RP and appeared to be associated with small-molecular-mass protein complexes in cytosolic fractions, where PUB22 and PUB23 are localized. Overall, our results suggest that PUB22 and PUB23 coordinately control a drought signaling pathway by ubiquitinating cytosolic RPN12a in Arabidopsis.
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PMID:Arabidopsis PUB22 and PUB23 are homologous U-Box E3 ubiquitin ligases that play combinatory roles in response to drought stress. 1866 14

Many neurodegenerative diseases are characterized by deposits of ubiquitinated and aberrant proteins, suggesting a failure of the ubiquitin-proteasome system (UPS). The aberrant ubiquitin UBB(+1) is one of the ubiquitinated proteins accumulating in tauopathies such as Alzheimer's disease (AD) and polyglutamine diseases such as Huntington's disease. We have generated UBB(+1) transgenic mouse lines with post-natal neuronal expression of UBB(+1), resulting in increased levels of ubiquitinated proteins in the cortex. Moreover, by proteomic analysis, we identified expression changes in proteins involved in energy metabolism or organization of the cytoskeleton. These changes show a striking resemblance to the proteomic profiles of both AD brain and several AD mouse models. Moreover, UBB(+1) transgenic mice show a deficit in contextual memory in both water maze and fear conditioning paradigms. Although UBB(+1) partially inhibits the UPS in the cortex, these mice do not have an overt neurological phenotype. These mouse models do not replicate the full spectrum of AD-related changes, yet provide a tool to understand how the UPS is involved in AD pathological changes and in memory formation.
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PMID:Long-term proteasome dysfunction in the mouse brain by expression of aberrant ubiquitin. 1876 May 6


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