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1.
An ESR study of nitrosyl-Aplysia brasiliana myoglobin and nitrosyl annelidae Glossoscolex paulistus erythrocruorin 总被引:1,自引:0,他引:1
I Caracelli N C Meirelles M Tabak O Baffa Filho O R Nascimento 《Biochimica et biophysica acta》1988,955(3):315-320
The nitrosyl derivatives of Annelidae Glossoscolex paulistus hemoglobin (an earth worm erythrocruorin (Ec AGp)) and Aplysia brasiliana myoglobin (Mb Apb) are studied using ESR spectroscopy. These two proteins have a quite similar ESR spectra at 100 K, but a different temperature behaviour. The temperature dependence of the nitrosyl Mb Apb spectrum is in good agreement with the Boltzmann distribution. In the case of nitrosyl-Ec AGp, the results are explained by the existence of two types of spectrum in thermodynamic equilibrium, with delta H = 9.08 kJ/mol, delta S = 47.15 J/mol and T1/2 = 193 K. There is a great similarity of the nitrosyl-Ec AGp spectra with those reported for elephant myoglobin, suggesting the presence of the same heme environment with a glutamine residue in the distal site. The pH dependence of the spectrum of nitrosyl-Mb Apb shows that the affinity of nitrosyl binding is higher at high pH (7.3) than at low pH (4.6). The ESR parameters are the same for these two pH values. 相似文献
2.
Nineflavonoids: a dihydrochalcone,a flavone,four 3-methylflavonols,a flavanone, a 3-methylflavanonol and a flavan were isolated from the roots of Derris araripensis. Eight of these compounds are reported for the first time. Structures were established by spectral analysis and chemical degradation. 相似文献
3.
Soares TN Melo DB Resende LV Vianello RP Chaves LJ Collevatti RG Telles MP 《American journal of botany》2012,99(2):e72-e73
? Premise of the study: Microsatellite markers were developed for the population genetic analyses of the neotropical tree Dipteryx alata (Fabaceae). ? Methods and Results: Microsatellites were developed from a genomic shotgun library. Polymorphism at each microsatellite loci was analyzed based on 94 individuals from three populations. Eight loci amplified successfully and presented one to 10 alleles, and expected heterozygosities ranged from 0.097 to 0.862. Four loci also amplified in Pterodon emarginatus and presented similar polymorphism. ? Conclusion: The eight microsatellite primer pairs are potentially suitable for population genetic studies and successfully amplified in another Fabaceae species. 相似文献
4.
Iris M Costa Tallybia HT Nasser Marilene Demasi Rafaella MP Nascimento Luis ES Netto Sayuri Miyamoto Fernanda M Prado Gisele Monteiro 《BMC microbiology》2011,11(1):268
Background
The gene YCL047C, which has been renamed promoter of filamentation gene (POF1), has recently been described as a cell component involved in yeast filamentous growth. The objective of this work is to understand the molecular and biological function of this gene.Results
Here, we report that the protein encoded by the POF1 gene, Pof1p, is an ATPase that may be part of the Saccharomyces cerevisiae protein quality control pathway. According to the results, Δpof1 cells showed increased sensitivity to hydrogen peroxide, tert-butyl hydroperoxide, heat shock and protein unfolding agents, such as dithiothreitol and tunicamycin. Besides, the overexpression of POF1 suppressed the sensitivity of Δpct1, a strain that lacks a gene that encodes a phosphocholine cytidylyltransferase, to heat shock. In vitro analysis showed, however, that the purified Pof1p enzyme had no cytidylyltransferase activity but does have ATPase activity, with catalytic efficiency comparable to other ATPases involved in endoplasmic reticulum-associated degradation of proteins (ERAD). Supporting these findings, co-immunoprecipitation experiments showed a physical interaction between Pof1p and Ubc7p (an ubiquitin conjugating enzyme) in vivo.Conclusions
Taken together, the results strongly suggest that the biological function of Pof1p is related to the regulation of protein degradation.5.
6.
Dam TK Cavada BS Nagano CS Rocha BA Benevides RG Nascimento KS de Sousa LA Oscarson S Brewer CF 《Glycobiology》2011,21(7):925-933
The legume species of Cymbosema roseum of Diocleinae subtribe produce at least two different seed lectins. The present study demonstrates that C. roseum lectin I (CRL I) binds with high affinity to the "core" trimannoside of N-linked oligosaccharides. Cymbosema roseum lectin II (CRL II), on the other hand, binds with high affinity to the blood group H trisaccharide (Fucα1,2Galα1-4GlcNAc-). Thermodynamic and hemagglutination inhibition studies reveal the fine binding specificities of the two lectins. Data obtained with a complete set of monodeoxy analogs of the core trimannoside indicate that CRL I recognizes the 3-, 4- and 6-hydroxyl groups of the α(1,6) Man residue, the 3- and 4-hydroxyl group of the α(1,3) Man residue and the 2- and 4-hydroxyl groups of the central Man residue of the trimannoside. CRL I possesses enhanced affinities for the Man5 oligomannose glycan and a biantennary complex glycan as well as glycoproteins containing high-mannose glycans. On the other hand, CRL II distinguishes the blood group H type II epitope from the Lewis(x), Lewis(y), Lewis(a) and Lewis(b) epitopes. CRL II also distinguishes between blood group H type II and type I trisaccharides. CRL I and CRL II, respectively, possess differences in fine specificities when compared with other reported mannose and fucose recognizing lectins. This is the first report of a mannose-specific lectin (CRL I) and a blood group H type II-specific lectin (CRL II) from seeds of a member of the Diocleinae subtribe. 相似文献
7.
The reaction of [nitrotyrosyl]cytochrome c with ligands was studied by stopped-flow techniques. At pH 7.0 the reaction with imidazole shows two distinct phases, one fast phase being concentration-dependent and a slow phase being concentration-independent. The results are consistent with the existence of two forms of [nitrotyrosyl]cytochrome c in solutions [Schejter et al. (1970) Biochemistry 9, 5118-5122]; form I, the smaller fraction, seems to be responsible for the slow first-order process. 相似文献
8.
S. B. do Nascimento Tavares N. L. A. de Sousa E. J. C. Manrique Z. B. P. de Albuquerque L. C. Zeferino R. G. Amaral 《Cytopathology》2008,19(4):254-259
Objective: To evaluate the performance of rapid pre-screening (RPS) as a method of internal quality control in the cytopathological examination of cervical smears for cervical cancer screening.
Methods: The sample consisted of 6135 cervical smears submitted to RPS and routine screening (RS) methods. The smears classified as negative in RPS and RS were considered final diagnoses, and were not, therefore, submitted to any additional review. The smears identified as suspect or unsatisfactory according to RPS were analysed separately by two different cytologists irrespective of the diagnosis reached in RS. Smears considered abnormal or unsatisfactory at RS were also reviewed. When both cytologists issued concordant diagnoses, this was considered the final diagnosis. Discordant results were analysed by a third cytologist and a consensus meeting was held to define the final diagnosis.
Results: Taking abnormalities detected by RS as the denominator, RPS had a sensitivity of 63.0% for the detection of all abnormal smears and 96.7% for high grade squamous intraepithelial lesion (HSIL). When compared with the final diagnosis, sensitivity of RPS for all abnormal smears was 74.9% and for HSIL 95.0%. Of the 529 abnormal smears confirmed in the final diagnosis, 2.15% were detected only by the RPS.
Conclusion: RPS is an effective alternative method of internal quality control with high sensitivity for the detection of more severe lesions. It also permits monitoring of the laboratory rate of false-negative results, and allows constant evaluation of the performance both of the pre-screening and RS cytologists. 相似文献
Methods: The sample consisted of 6135 cervical smears submitted to RPS and routine screening (RS) methods. The smears classified as negative in RPS and RS were considered final diagnoses, and were not, therefore, submitted to any additional review. The smears identified as suspect or unsatisfactory according to RPS were analysed separately by two different cytologists irrespective of the diagnosis reached in RS. Smears considered abnormal or unsatisfactory at RS were also reviewed. When both cytologists issued concordant diagnoses, this was considered the final diagnosis. Discordant results were analysed by a third cytologist and a consensus meeting was held to define the final diagnosis.
Results: Taking abnormalities detected by RS as the denominator, RPS had a sensitivity of 63.0% for the detection of all abnormal smears and 96.7% for high grade squamous intraepithelial lesion (HSIL). When compared with the final diagnosis, sensitivity of RPS for all abnormal smears was 74.9% and for HSIL 95.0%. Of the 529 abnormal smears confirmed in the final diagnosis, 2.15% were detected only by the RPS.
Conclusion: RPS is an effective alternative method of internal quality control with high sensitivity for the detection of more severe lesions. It also permits monitoring of the laboratory rate of false-negative results, and allows constant evaluation of the performance both of the pre-screening and RS cytologists. 相似文献
9.
Nara F. Nascimento Jasmin A. Hicks Karen N. Carlson Aikaterini Hatzidis Danielle N. Amaral Ryan W. Logan 《Chronobiology international》2016,33(1):108-116
Studies have shown a relationship between circadian rhythm disruptions and type-2 diabetes. This investigation examined the effects of circadian disruption (6-h phase advances) on the progression of diabetes in a type-2 diabetic mouse model –TALLYHO/JngJ – and whether wheel-running can alleviate the effects of the phase advances. 6-h advances alter fasting glucose, glucose tolerance and insulin production. Wheel-running reduced body mass, improved glucose tolerance and reduced insulin in TALLYHO/JngJ and alleviated some of the changes in diabetic symptoms due to 6-h advances. These results indicate that individuals with type-2 diabetes can benefit from physical activity and exercise can be a countermeasure to offset the effects of an acute phase advance. 相似文献
10.
A chemically defined medium for Veillonella parvula and V. alcalescens is described. Some nutritional aspects of the two strains used were examined: the optimum concentration of reducing agents, the requirement for amino acids, diamines, vitamins and other growth factors, and the conditions needed for well balanced nutrition.No specific requirements for single amino acids were observed. A combination of l-cysteine, dl-aspartic acid, l-glutamic acid, l-serine and l-tyrosine, promoted growth. In V. alcalescens, serine could substitute both arginine and tryptophan (or histidine). No growth was obtained with ammonium salts as the sole N source.Decarboxylation of l-ornithine, l-lysine and l-arginine was not demonstrated in the Veillonella parvula strain, which required putrescine or cadaverine for growth. Spermine, spermidine, l-lysine, l-ornithine and l-arginine, could not substitute putrescine in Veillonella parvula. Veillonella alcalescens, which does not require putrescine in the medium, was able to decarboxylate l-ornithine while forming putrescine. 相似文献