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1.
Filippo Genovese Stefania Ferrari Giambattista Guaitoli Monica Caselli M. Paola Costi Glauco Ponterini 《Protein science : a publication of the Protein Society》2010,19(5):1023-1030
An ad hoc bioconjugation/fluorescence resonance energy transfer (FRET) assay has been designed to spectroscopically monitor the quaternary state of human thymidylate synthase dimeric protein. The approach enables the chemoselective engineering of allosteric residues while preserving the native protein functions through reversible masking of residues within the catalytic site, and is therefore suitable for activity/oligomerization dual assay screenings. It is applied to tag the two subunits of human thymidylate synthase at cysteines 43 and 43′ with an excitation energy donor/acceptor pair. The dimer–monomer equilibrium of the enzyme is then characterized through steady‐state fluorescence determination of the intersubunit resonance energy transfer efficiency. 相似文献
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Paola A Gilardoni Stefan Schuck Ruth Jüngling Björn Rotter Ian T Baldwin Gustavo Bonaventure 《BMC plant biology》2010,10(1):66
Background
Plants trigger and tailor defense responses after perception of the oral secretions (OS) of attacking specialist lepidopteran larvae. Fatty acid-amino acid conjugates (FACs) in the OS of the Manduca sexta larvae are necessary and sufficient to elicit the herbivory-specific responses in Nicotiana attenuata, an annual wild tobacco species. How FACs are perceived and activate signal transduction mechanisms is unknown. 相似文献4.
Summary The biosynthesis of rhodanese was studied in human hepatoma cell lines by immunoblotting and pulselabeling experiments using polyclonal antibodies raised against the bovine liver enzyme. Rhodanese, partially purified from human liver, showed an apparent molecular weight of 33,000 daltons, coincident with that of rhodanese from Hep 3B cells. After pulse labeling of Hep 3B cells both at 37°C and 25°C, rhodanese in the cytosol fraction exhibited the same molecular weight as the enzyme isolated from the particulate fraction containing mitochondria. Moreover, newly synthesized rhodanese from total Hep 3B RNA translation products showed the same electrophoretic mobility as rhodanese from Hep 3B cells. These results suggest that rhodanese, unlike most mitochondrial proteins, is not synthesized as a higher molecular weight precursor. 相似文献
5.
Paola Cescutti Neil Ravenscroft Stephen Ng Zamas Lam Guy G.S. Dutton 《Carbohydrate research》1983,244(2):325-340
The capsular polysaccharide of Klebsiella SK1 was investigated by methylation analysis, Smith degradation, and 1H NMR spectroscopy. The oligosaccharides (P1 and P2) obtained by bacteriophage ΦSK1 degradation of the polymer were studied by methylation analysis, and 1D- and 2D-NMR spectroscopy. The resulting data showed that the patent repeating unit is a branched pentasaccharide having a structure identical to the revised structure recently proposed for Klebsiella serotype K8 capsular polysaccharide. The 2D-NMR data showed that one third of the glucuronic acid residues in the SK1 polymer are acetylated at O-2, O-3, or O-4. FABMS studies confirmed the presence of monoacetylated glucuronic acid residues. Thus, the relationship between the Klebsiella K8 and SK1 polymers is akin to that found for Klebsiella polysaccharides K30 and K33, which have been typed as serologically distinct yet their structures differ only in the degree of acetylation. 相似文献
6.
Fabrizio Villani Milena Galimberti Elena Monti Francesco Piccinini Enrica Lanza Annalinda Rozza Luigia Favalli Paola Poggi Franco Zunino 《Free radical research》1990,11(1):145-151
The effects of two sulfhydryl compounds, glutathione (GSH) and N-acetylcysteine (NAC), on the cardiotoxicity of doxorubicin (DXR) were tested on in vitro and in vivo models. DXR was administered to rats as 4 weekly i.v. doses of 3mg/kg. GSH (1.5 mmoles/kg), given i.v. 10 min before and 1 hr after DXR, was found to prevent the development of the delayed cardiotoxic effects of DXR, as assessed by electrocardiographic and mechanical parameters, as well as by histological examination of left ventricular preparations. In contrast, equimolar oral doses of NAC (1 hr before and 2hrs after DXR) were found to be ineffective. Both GSH and NAC prevented the negative inotropic effect produced by DXR on isolated rat atria. A good correlation exists between the cardioprotective effects of the two agents and their ability to enhance the non-protein sulfhydryl group content of the myocardium. Differences observed in vivo between GSH and NAC might be accounted for by pharmacokinetic factors. 相似文献
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Jose Pontón Fernando L. Hernando Maria Dolores Moragues Pedro L. Barea Mara Gerloni Stefania Conti Paola Fisicaro Cristina Cantelli Luciano Polonelli 《Mycopathologia》1996,133(2):89-94
The presence of heat shock mannoproteins (HSMPs) reactive with sIgA was demonstrated in several C. albicans strains. The subculture of the C. albicans isolated from mucosal surfaces on Sabouraud's dextrose agar at 25 °C switched off the HSMP expression. A re-expression of the HSMPs was obtained in the same medium by shifting the temperature of incubation to 37 °C. However, expression of HSMPs in two strains isolated from deep infections was maintained during several subcultures on Sabouraud's dextrose agar at 25 °C. A glycoprotein of 200 kDa seemed to be the main HSMP reacting with vaginal sIgA. The data presented in this study suggest that factors other than temperature can influence the expression of C. albicans HSMPs and therefore these antigens should be referred as stress mannoproteins.Abbreviations HSMPs
heat shock mannoproteins
- MAb
monoclonal antibody
- sIgA
secretory IgA 相似文献
9.
David Bouchez Paola Vittorioso Béatrice Courtial Christine Camilleri 《Plant Molecular Biology Reporter》1996,14(2):115-123
We have designed a new method for the recovery of T-DNA flanking sequences from T-DNA-tagged lines ofArabidopsis thaliana. Since most transformation vectors in use contain a plant-selectable marker for kanamycin resistance, we can use the 3′ part
of thenptII coding region from the T-DNA to complement the bacterial 5′ region of thenptII gene from Tn5 to reconstruct a functional kanamycin-resistance gene inEscherichia coli. We have constructed a vector that contains the 5′ part of thenptII gene from Tn5 up to the uniquePst I site. By cloning total DNA from transformed lines in this vector, we were able to select directly for clones containing
a T-DNA fragment, which reconstitutes a functional kanamycin gene, and a fragment of arabidopsis genomic DNA adjacent to the
insertion. Flanking sequences up to 4 kb were rescued by this system. 相似文献
10.