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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:	BIBFORM004740
035-os BibID:	(WOS)000184609400011 (scopus)12444317206
Első szerző:	Szilágyi Ildikó (orvos)
Cím:	Non-random features of loop-size chromatin fragmentation / Szilagyi, I., Varga, T., Szekvolgyi, L., Hegedus, E., Goda, K., Kaczur, V., Bacso, Z., Nakayama, Y., Posafi, J., Pongor, S., Szabo, G.
Dátum:	2003
ISSN:	730-2312 (Print)
Megjegyzések:	Upon isolation of DNA from normal eukaryotic cells by standard methods involving extensive proteolytic treatment, a rather homogeneous population of loop-size, double-stranded DNA fragments is regularly obtained. These DNA molecules can be efficiently end-labeled by the DNA polymerase I Klenow fragment, as well as by a 3'- to -5'-exonuclease-free Klenow enzyme, but not by terminal transferase (TdT) unless the ends have been filled up by Klenow, suggesting that dominantly 5' protruding termini are generated upon fragmentation. The filled-up termini were used for cloning the distal parts of the approximately 50 kb fragments. BLAST analysis of the sequence of several clones allowed us to determine the sequence of the non-cloned side of the breakpoints. Comparison of 25, 600 bp-long breakpoint sequences demonstrated prevalence of repetitive elements. Consensus motives characteristic of the breakpoint sequences have been identified. Several sequences exhibit peculiar computed conformational characteristics, with sharp transition or center of symmetry located exactly at the breakpoint. Our data collectively suggest that chromatin fragmentation involves nucleolytic cleavages at fragile/hypersensitive sites delimiting loop-size fragments in a non-random manner. Interestingly, the sequence characteristics of the breakpoints are reminiscent of certain breakpoint cluster regions frequently subject to gene rearrangements.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk analysis Animals Base Sequence Biophysics Cells chemistry Chromatin Dna DNA Fragmentation DNA Nucleotidylexotransferase DNA Polymerase I Electrophoresis,Gel,Two-Dimensional Eukaryotic Cells HL-60 Cells Humans Hungary isolation and purification Jurkat Cells methods Mice Nih 3T3 Cells Prevalence Research Sequence Analysis,DNA Support egyetemen (Magyarországon) készült közlemény
Megjelenés:	Journal of Cellular Biochemistry. - 89 : 6 (2003), p. 1193-1205. -
További szerzők:	Varga Tamás (1971-) (biológus) Székvölgyi Lóránt (1977-) (biofizikus, biokémikus, sejtbiológus) Hegedűs Éva (1978-) (biofizikus) Goda Katalin (1969-) (biofizikus) Kaczur Viktória Bacsó Zsolt (1963-) (biofizikus) Nakayama, Yuji Pósafi János Pongor Sándor Szabó Gábor (1953-) (biofizikus)
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