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001-es BibID:	BIBFORM006025
Első szerző:	Balázs Margit (sejtbiológus, molekuláris genetikus)
Cím:	Fluorescent tetradecanoylphorbol acetate : a novel probe of phorbol ester binding domains / Balázs, M., Szöllösi, J., Lee, W. C., Haugland, R. P., Guzikowski, A. P., Fulwyler, M. J., Damjanovich, S., Feuerstein, B. G., Pershadsingh, H. A.
Dátum:	1991
Megjegyzések:	Protein kinase C (PKC) has a prominent role in signal transduction of many bioactive substances. We synthesized the fluorescent derivative, phorbol-13-acetate-12-N-methyl-N-4-(N,N'-di(2-hydroxyethyl)amino)-7-n itr obenz-2-oxa-1,3-diazole-aminododecanoate (N-C12-Ac(13)) of 12-O-tetradecanoylphorbol-13-acetate (TPA) to monitor the location of phorbol ester binding sites and evaluate its potential use as a probe of PKC in viable cells. The excitation maximum wavelength of N-C12-Ac(13) is close to 488 nm, facilitating its use in argon-ion laser flow and imaging cytometry. When incubated with 100 nM N-C12-Ac(13) at 25 degrees C, P3HR-1 Burkitt lymphoma cells accumulated the dye rapidly, reaching maximum fluorescence within 25 min, 20-fold above autofluorescence. Addition of unlabeled TPA significantly decreased the fluorescence of N-C12-Ac(13) stained cells in a dose-dependent manner indicating specific displacement of the bound fluoroprobe. Competitive displacement of [3H]-phorbol-12,13-dibutyrate ([3H]-PBu2) from rat brain cytosol with N-C12-Ac(13) gave an apparent dissociation constant (Kd) of 11 nM. N-C12-Ac(13) possessed biological activity similar to TPA. Like TPA (final concentration 65 nM) N-C12-Ac(13), at a lower concentration (51 nM), induced expression of Epstein-Barr viral glycoprotein in P3HR-1 cells, differentiation of promyelocytic HL60 cells, and caused predicted changes in the mitotic cycle of histiocytic DD cells. Microspectrofluorometric images of single cells labeled with N-C12-Ac(13) showed bright fluorescence localized intracellularly and dim fluorescence in the nuclear region, consistent with dye binding mainly to cytoplasmic structures and/or organelles and being mostly excluded from the nucleus. Because of the high level of non-specific binding of N-C12-Ac(13), this probe is not ideal for visualizing PKC in intact cells, but would be a valuable fluoroprobe to investigate the kinetic properties of purified PKC. Also, knowledge gained from these studies allows us to predict structures of fluorescent phorbols likely to have less non-specific binding and, consequently, be potentially useful for monitoring PKC in viable cells.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban analysis Animal Antigens,Viral Binding Sites Brain Chemistry Cell Cycle chemical synthesis Cytosol Dyes Female Flow Cytometry Fluorescence Fluorescence Polarization Fluorescent Dyes Gene Expression Herpesvirus 4,Human Image Processing,Computer-Assisted immunology metabolism Oxadiazoles pharmacology Phorbol Esters Protein Kinase C Rats Rats,Inbred Strains Signal Transduction Support,Non-U.S.Gov't Support,U.S.Gov't,P.H.S. Tetradecanoylphorbol Acetate Tumor Cells,Cultured
Megjelenés:	Journal of Cellular Biochemistry. - 46 : 3 (1991), p. 266-276. -
További szerzők:	Szöllősi János (1953-) (biofizikus) Lee, W. C. Haugland, R. P. Guzikowski, A. P. Fulwyler, Mack J. Damjanovich Sándor (1936-2017) (biofizikus) Feuerstein, Burt G. Pershadsingh, Harrihar A.
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001-es BibID:	BIBFORM005984
Első szerző:	Matkó János (biológus)
Cím:	Correlation between activity and dynamics of the protein matrix of phosphorylase b / Janos Matko, Lajos Tron, Margit Balazs, Jozsef Hevessy, Bela Somogyi, Sandor Damjanovich
Dátum:	1980
Megjegyzések:	Quenching of the tryptophan fluorescence of phosphorylase b was studied by using iodide and acrylamide. Steady-state measurements indicated that all indole side chains were accessible to the nonionic quencher, although only 3 out of the total of 12 residues could be quenched by I-. From Stern--Volmer plots and the fluorescence lifetime data, it was concluded that the quenching was mainly of dynamic character. The value of the collisional quenching rate constant was found to be an order of magnitude less than that obtained in the case of fully exposed tryptophans. The relatively high activation energy, 30.9 kJ/mol, of the diffusion-controlled process and the value of the activation entropy suggest that the diffusion takes place in a fluctuating, structured medium. In spite of the application of sensitive fluorescent techniques, no gross conformational changes were found in the presence of acrylamide. However, the catalytic rate of the glycogen synthesis was decreased with the residual activity of the enzyme, proportional to the concentration of the probe. Binding of activator (AMP) and substrates (glucose 1-phosphate and glycogen) was found to be unaffected by acrylamide in concentrations applied (0--0.8 M). In a similar manner, activation enthalpy did not change in the presence of the quencher either. The complete reversibility of both activity inhibition and fluorescence quenching ruled out the irreversible denaturation of the enzyme or the covalent modification of any of the functional groups. We concluded that a model, suggesting the cross-correlation of activity and fluctuation, was consistent with the experimental findings.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Acrylamides Animal Diffusion enzymology Fluorescence Glucose Iodides Kinetics Ligands metabolism Muscles pharmacology Phosphorylase b Phosphorylases Protein Denaturation Rabbits Spectrometry,Fluorescence Tryptophan
Megjelenés:	Biochemistry. - 19 : 25 (1980), p. 5782-5786. -
További szerzők:	Trón Lajos (1941-) (biofizikus) Balázs Margit (1952-) (sejtbiológus, molekuláris genetikus) Hevessy József Somogyi Béla (1945-2006) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus)
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001-es BibID:	BIBFORM006055
035-os BibID:	PM:2272119
Első szerző:	Timár József
Cím:	Modulation of membrane phenotype, matrix adhesion and microinvasiveness of metastatic tumour cells by HUdR / Timar, J., Pogany, G., Balazs, M., Szollosi, J., Ladanyi, A., Olah, J., Timar, F., Lapis, K., Jeney, A.
Dátum:	1990
Megjegyzések:	The effect of HUdR, proved to be anti-metastatic in vivo, was studied in vitro on cell proliferation, nucleoside uptake, membrane fluidity, expression of galactosylated glycans and proteoglycans in metastatic HM tumour cells. The observed increase in membrane fluidity and the suppression of nucleoside transport were early events of the HUdR action followed by decrease of galactosylated glycan and HSPG expression. However, these changes did not influence the proliferation capacity of the cells at the concentrations studied. As a consequence of the membrane alterations a reduced adhesiveness and spreading on extracellular matrix components was detected. In addition, the HUdR treated HM cells showed reduced capacity to invade fibroblast monolayers in vitro. Based on these observations, HUdR could be the prototype of new anti-metastatic agents acting at the level of tumour-host interaction.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban analysis Animal Antimetabolites,Antineoplastic Cell Adhesion Cell Division Cell Membrane chemistry Deoxyuridine diagnostic use drug effects Extracellular Matrix Glycoconjugates Human Hungary immunology In Vitro Membrane Fluidity metabolism Neoplasm Invasiveness Nucleosides pathology pharmacology Phenotype physiology Proteoglycans Research Tritium
Megjelenés:	Cell Biochemistry and Function. - 8 : 4 (1990), p. 211-220. -
További szerzők:	Pogány G. Balázs Margit (1952-) (sejtbiológus, molekuláris genetikus) Szöllősi János (1953-) (biofizikus) Ladányi A. Oláh J. Timár F. Lapis Károly Jeney A.
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