Imine Ligands Based on Ferrocene: Synthesis, Structural and Mössbauer Characterization and Evaluation as Chromogenic and Electrochemical Sensors for Hg+2,
Rosa, V., Gaspari A., Folgosa F., Cordas C. M., Tavares P., Santos-Silva T., Barroso S., and Avilés T.
, New J Chem, Volume 42, p.3334-3343, (2018)
Implications of oxidovanadium (IV) binding to actin,
Ramos, S., Almeida R. M., Moura J. J., and Aureliano M.
, Eur J Inorg Chem, Volume 105, Issue 6, p.777, (2011)
Implications of oxidovanadium(IV) binding to actin,
Ramos, S., Almeida R. M., Moura J. J., and Aureliano M.
, J Inorg Biochem, Jun, Volume 105, Number 6, p.777-83, (2010)
AbstractOxidovanadium(IV), a cationic species (VO(2+)) of vanadium(IV), binds to several proteins, including actin. Upon titration with oxidovanadium(IV), approximately 100% quenching of the intrinsic fluorescence of monomeric actin purified from rabbit skeletal muscle (G-actin) was observed, with a V(50) of 131 muM, whereas for the polymerized form of actin (F-actin) 75% of quenching was obtained and a V(50) value of 320 muM. Stern-Volmer plots were used to estimate an oxidovanadium(IV)-actin dissociation constant, with K(d) of 8.2 muM and 64.1 muM VOSO(4), for G-actin and F-actin, respectively. These studies reveal the presence of a high affinity binding site for oxidovanadium(IV) in actin, producing local conformational changes near the tryptophans most accessible to water in the three-dimensional structure of actin. The actin conformational changes, also confirmed by (1)H NMR, are accompanied by changes in G-actin hydrophobic surface, but not in F-actin. The (1)H NMR spectra of G-actin treated with oxidovanadium(IV) clearly indicates changes in the resonances ascribed to methyl group and aliphatic regions as well as to aromatics and peptide-bond amide region. In parallel, it was verified that oxidovanadium(IV) prevents the G-actin polymerization into F-actin. In the 0-200 muM range, VOSO(4) inhibits 40% of the extent of polymerization with an IC(50) of 15.1 muM, whereas 500 muM VOSO(4) totally suppresses actin polymerization. The data strongly suggest that oxidovanadium(IV) binds to actin at specific binding sites preventing actin polymerization. By affecting actin structure and function, oxidovanadium(IV) might be responsible for many cellular effects described for vanadium.
Improving sample treatment for in-solution protein identification by peptide mass fingerprint using matrix-assisted laser desorption/ionization time-of-flight mass Spectrometry,
Santos, H. M., Rial-Otero R., Fernandes L., Vale G., Rivas M. G., Moura I., and Capelo J. L.
, Journal of Proteome Research, Sep, Volume 6, Number 9, p.3393-3399, (2007)
AbstractThree ultrasonic energy sources were studied to speed up the sample treatment for in-solution protein identification by peptide mass fingerprint using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Protein reduction, alkylation, and enzymatic digestion steps were done in 15 min. Nine proteins, including zinc resistance-associated protein precursor from Desulfovibrio desulfuricans strain G20 and split-soret cytochrome c from D. desulfuricans ATCC27774 were successfully identified with the new protocol.
Induced peroxidase activity of haem containing nitrate reductases revealed by protein film electrochemistry,
Coelho, C., Marangon J., Rodrigues D., Moura J. J. G., Romão M. J., Paes de Sousa P. M., and Correia dos Santos M. M.
, J Electroanal Chem, Volume 693, p.105-113, (2013)
Influence of storage solution on enamel demineralization submitted to pH cycling,
Moura, J. S., Rodrigues L. K., Del Bel Cury A. A., Lima E. M., and Garcia R. M.
, J Appl Oral Sci, Sep, Volume 12, Number 3, p.205-8, (2004)
AbstractExtracted human teeth are frequently used for research or educational purposes. Therefore, it is necessary to store them in disinfectant solutions that do not alter dental structures. Thus, this study evaluated the influence of storage solution on enamel demineralization. For that purpose, sixty samples were divided into the following groups: enamel stored in formaldehyde (F1), stored in thymol (T1), stored in formaldehyde and submitted to pH cycling (F2), stored in thymol and submitted to pH cycling (T2). All samples were evaluated by cross-sectional microhardness analysis and had their percentage of mineral volume versus micrometer (integrated area) determined. Differences between groups were found up to 30-microm depth from the enamel surface (p < 0.05), where samples from group T2 were more demineralized. It was concluded that the storage solution influenced the reaction of a dental substrate to a cariogenic challenge, suggesting that formaldehyde may increase enamel resistance to demineralization, when compared to demineralization occurring in enamel stored in thymol solution.
Influence of the protein staining in the fast ultrasonic sample treatment for protein identification through peptide mass fingerprint and matrix-assisted laser desorption ionization time of flight mass spectrometry,
Galesio, M., Vieira D. V., Rial-Otero R., Lodeiro C., Moura I., and Capelo J. L.
, Journal of Proteome Research, May, Volume 7, Number 5, p.2097-2106, (2008)
AbstractThe influence of the protein staining used to visualize protein bands, after in-gel protein separation, for the correct identification of proteins by peptide mass fingerprint (PMF) after application of the ultrasonic in-gel protein protocol was studied. Coomassie brilliant blue and silver nitrate, both visible stains, and the fluorescent dyes Sypro Red and Sypro Orange were evaluated. Results obtained after comparison with the overnight in-gel protocol showed that good results, in terms of protein sequence coverage and number of peptides matched, can be obtained with anyone of the four stains studied. Two minutes of enzymatic digestion time was enough for proteins stained with coomassie blue, while 4 min was necessary when silver or Sypro stainings were employed in order to reach equivalent results to those obtained for the overnigh in-gel protein protocol. For the silver nitrate stain, the concentration of silver present in the staining solution must be 0.09% (w/v) to minimize background in the MALDI mass spectra.