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41.
Hypoxia-inducible factor 1 transactivates the human leptin gene promoter 总被引:15,自引:0,他引:15
Grosfeld A Andre J Hauguel-De Mouzon S Berra E Pouyssegur J Guerre-Millo M 《The Journal of biological chemistry》2002,277(45):42953-42957
42.
Nikola Hadzi‐Petrushev Marija Angelovski Katerina Rebok Vadim Mitrokhin Andre Kamkin Mitko Mladenov 《Journal of biochemical and molecular toxicology》2019,33(8)
For 22 days after monocrotaline injection two groups of rats received either of the monocarbonyl curcumin analogs (2E,6E)‐2,6‐bis(2‐bromobenzylidene)cycloxehanone (B2BrBC) and (2E,6E)‐2,6‐bis([2‐tri?uoromethyl]benzylidene)cyclohexanone (C66), and their right ventricle parameters were compared to those from the control and the monocrotaline injected animals. B2BrBC and C66 treatments did not prevent the monocrotaline‐induced right ventricular hypertrophy but attenuated the changes in antioxidant enzyme activities and reduced inflammation. The level of thiol‐based nonenzymatic antioxidants did not change in the function of monocrotaline or curcumin analogs treatment. However, due to its stronger antioxidant properties, only B2BrBC treatment was effective in the reduction of monocrotaline‐associated lipid peroxidation. The obtained results suggest that increasing the levels of antioxidant enzymes may not be sufficient to reduce oxidative stress and chronic inflammation optimally and our current study supports the potential of compounds with more than one beneficial biological activity as a promising treatment against the progression of cardiac hypertrophy. 相似文献
43.
44.
Maria Lígia Rodrigues Macedo Maria das Graas Machado Freire Maria Barbosa Reis da Silva Luana Cassandra Breitenbach Barroso Coelho 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2007,146(4):486
Bruchid beetle larvae cause major losses in grain legume crops throughout the world. Some bruchid species, such as the cowpea weevil (Callosobruchus maculatus) and the Mexican bean weevil (Zabrotes subfasciatus), are pests that damage stored seeds. The Mediterranean flour moth (Anagasta kuehniella) is of major economic importance as a flour and grain feeder; it is often a severe pest in flour mills. Plant lectins have been implicated as antibiosis factors against insects. Bauhinia monandra leaf lectin (BmoLL) was tested for anti-insect activity against C. maculatus, Z. subfasciatus and A. kuehniella larvae. BmoLL produced ca. 50% mortality to Z. subfaciatus and C. maculatus when incorporated into an artificial diet at a level of 0.5% and 0.3% (w/w), respectively. BmooLL up to 1% did not significantly decrease the survival of A. kuehniella larvae, but produced a decrease of 40% in weight. Affinity chromatography showed that BmoLL bound to midgut proteins of the insect C. maculatus. 33 kDa subunit BmoLL was not digested by midgut preparations of these bruchids. BmoLL-fed C. maculatus larvae increased the digestion of potato starch by 25% compared with the control. The transformation of the genes coding for this lectin could be useful in the development of insect resistance in important agricultural crops. 相似文献
45.
Studies on kidney sialidase in normal and diabetic rats 总被引:1,自引:0,他引:1
Rat kidney cortex sialidase was studied using alpha-sialyl-(2----3)-[3H]lactitol and alpha-sialyl-(2----6)-[3H]lactitol as substrates. The enzyme was found mainly in the lysosomal fraction. Only 23% of the sialidase activity of this fraction could be solubilized by a combination of freezing-thawing, sonication and Triton X-100 treatment. The optimal pH for the lysosomal enzyme activity was 4.2 and the enzyme's Km values for alpha-sialyl-(2----3)-lactitol and alpha-sialyl-(2----6)-lactitol were 0.28 and 0.41 mM, respectively. The specific activity was twice as high with the former substrate than with the latter. Sialidase activities in dialyzed kidney cortex homogenates of streptozotocin-diabetic rats and of age-matched control rats were compared. The specific activity was found to be significantly increased in the diabetic animals when using both substrates 5950 +/- 720 (S.E.) dpm/h per mg protein (n = 7) vs. 3970 +/- 370 in the controls (n = 8) with alpha-sialyl-(2----3)-lactitol (P less than 0.025) and 2870 +/- 300 vs. 1820 +/- 170 with alpha-sialyl-(2----6)-lactitol (P less than 0.02). The activities were also found to be increased when expressed per whole kidney cortex (P less than 0.005 and P less than 0.001, respectively). The elevated sialidase activity in diabetic kidney cortex may be related to the reported decrease in sialic acid content of the glomerular basement membrane, which lowers its negative charges and which may contribute to an increased permeability to proteins. 相似文献
46.
47.
Structural data are reported for two highly potent antifolates, 2,4-diamino-5-[3',4'-dimethoxy-5'-(5-carboxy-1-pentynyl)]benzylpyrimidine (PY1011), with 5000-fold selectivity for Pneumocystis carinii dihydrofolate reductase (pcDHFR), relative to rat liver DHFR, and 2,4-diamino-5-[2-methoxy-5-(4-carboxybutyloxy)benzyl]pyrimidine (PY957), that has 80-fold selectivity for pcDHFR. Crystal structures are reported for NADPH ternary complexes with PY957 and pcDHFR, refined to 2.2 A resolution; with PY1011 and pcDHFR, refined to 2.0 A resolution; and with PY1011 and mouse DHFR (mDHFR), refined to 2.2 A resolution. These results reveal that the carboxylate of the omega-carboxyalkyloxy side chain of these inhibitors form ionic interactions with the conserved Arg in the substrate binding pocket of DHFR. These data suggest that the enhanced inhibitory activity of PY1011 compared with PY957 is, in part, due to the favorable contacts with Phe69 of pcDHFR by the methylene carbons of the inhibitor side chain that are oriented by the triple bond of the 1-pentynyl side chain. These contacts are not present in the PY957 pcDHFR complex, or in the PY1011 mDHFR complex. In the structure of mDHFR the site of Phe69 in pcDHFR is occupied by Asn64. These data also revealed a preference for an unusual parallel ring stacking interaction between Tyr35 of the active site helix and Phe199 of the C-terminal beta sheet in pcDHFR and by Tyr33 and Phe179 in mDHFR that is independent of bound ligand. A unique His174-His187 parallel ring stacking interaction was also observed only in the structure of pcDHFR. These ring stacking interactions are rarely found in any other protein families and may serve to enhance protein stability. 相似文献
48.
Aiko Kiso Koushi Hidaka Tooru Kimura Yoshio Hayashi Azin Nezami Ernesto Freire Yoshiaki Kiso 《Journal of peptide science》2004,10(11):641-647
Plasmepsin (Plm) has been identified as an important target for the development of new antimalarial drugs, since its inhibition leads to the starvation of Plasmodium falciparum. A series of substrate-based dipeptide-type Plm II inhibitors containing the hydroxymethylcarbonyl isostere as a transition-state mimic were synthesized. The general design principle was provision of a conformationally restrained hydroxyl group (corresponding to the set residue at the P2' position in native substrates) and a bulky unit to fit the S2' pocket. 相似文献
49.
Abstract The 5′-O-(4,4′-dimethoxytrityl) and 5′-O-(tert-butyldimethylsilyl) derivatives of 2′-,3′-O-thiocarbonyl-6-azauridine and 2′,3′-O-thiocarbonyl-5-chlorouridine were synthesized from the parent nucleosides by reaction with 4, 4′-dimethoxytrityl chloride and tert-butyldimethylsilyl chloride, respectively, followed by treatment with 1,1′-thiocarbonyldiimidazole. Introduction of a 2′-,3′-double bond into the sugar ring by reaction of the 5′-protected 2′-,3′-O-thionocarbonates with 1, 3-dimethyl-2-phenyl-1, 3, 2-diazaphospholidiine was unsuccessful, but could be accomplished satisfactorily with trimethyl phosphite. Reactions were generally more successful with the 5′-silylated than with the 5′-tritylated nucleosides. Formation of 2′-,3′-O-thiocarbonyl derivatives proceeded in higher yield with 5′-protected 6-azauridines than with the corresponding 5-chlorouridines because of the propensity of the latter to form 2,2′-anhydro derivatives. In the reaction of 5′-O-(tert-butyldimethylsilyl)-2′-,3′-O-thiocarbonyl-6-azauridine with trimethyl phosphite, introduction of the double bond was accompanied by N3-methylation. However this side reaction was not a problem with 5′-O-(tert-butyldimethylsilyl)-2′-, 3′-O-thioarbonyl-5-chlorouridine. Treatment of 5′-O-(tert-butyldimethylsilyl)-2′-, 3′-didehydro-2′-,3′-dideoxy-6-azauridine with tetrabutylammonium fluoride followed by hydrogenation afforded 2′-,3′-dideoxy-6-azauridine. Deprotection of 5′-O-(tert-butyldimethylsilyl)-2′-, 3′-didehydro-2′-,3′-dideoxy-5-chlorouridine yielded 2′-,3′-didehydro-2′-,3′-dide-oxy-5-chlorouridine. 相似文献
50.
Andre Menezes-Costa Erik Machado-Ferreira Carolina M. Voloch Cibele R. Bonvicino Hector N. Seuánez Orilio Leoncini Carlos A. G. Soares 《Microbial ecology》2013,66(2):471-478
Emerging infectious diseases usually arise from wild animal populations. In the present work, we performed a screening for bacterial infection in natural populations of New World primates. The blood cell bulk DNAs from 181 individuals of four Platyrrhini genera were PCR screened for eubacterial 16S rRNA genes. Bacteria were detected and identified in 13 distinct individuals of Alouatta belzebul, Alouatta caraya, and Cebus apella monkeys from geographically distant regions in the states of Mato Grosso and Pará, Brazil. Sequence analyses showed that these Platyrrhini bacteria are closely related not only to human pathogens Pseudomonas spp. but also to Pseudomonas simiae and sheep-Acari infecting Pseudomonas spp. The identified Pseudomonas possibly represents a group of bacteria circulating in natural monkey populations. 相似文献