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001-es BibID:	BIBFORM039514
Első szerző:	Matkó János (biológus)
Cím:	GPI-microdomains (membrane rafts) and signaling of the multi-chain interleukin-2 receptor in human lymphoma/leukemia T cell lines / Matko, J., Bodnar, A., Vereb, G., Bene, L., Vamosi, G., Szentesi, G., Szollosi, J., Gaspar, R., Horejsi, V., Waldmann, T. A., Damjanovich, S.
Dátum:	2002
ISSN:	0014-2956
Megjegyzések:	Subunits (alpha, beta and gamma) of the interleukin-2 receptor complex (IL-2R) are involved in both proliferative and activation-induced cell death (AICD) signaling of T cells. In addition, the signaling beta and gamma chains are shared by other cytokines (e.g. IL-7, IL-9, IL-15). However, the molecular mechanisms responsible for recruiting/sorting the alpha chains to the signaling chains at the cell surface are not clear. Here we show, in four cell lines of human adult T cell lymphoma/leukemia origin, that the three IL-2R subunits are compartmented together with HLA glycoproteins and CD48 molecules in the plasma membrane, by means of fluorescence resonance energy transfer (FRET), confocal microscopy and immuno-biochemical techniques. In addition to the beta and gamma(c) chains constitutively expressed in detergent-resistant membrane fractions (DRMs) of T cells, IL-2Ralpha (CD25) was also found in DRMs, independently of its ligand-occupation. Association of CD25 with rafts was also confirmed by its colocalization with GM-1 ganglioside. Depletion of membrane cholesterol using methyl-beta-cyclodextrin substantially reduced co-clustering of CD25 with CD48 and HLA-DR, as well as the IL-2 stimulated tyrosine-phosphorylation of STATs (signal transducer and activator of transcription). These data indicate a GPI-microdomain (raft)-assisted recruitment of CD25 to the vicinity of the signaling beta and gamma(c) chains. Rafts may promote rapid formation of a high affinity IL-2R complex, even at low levels of IL-2 stimulus, and may also form a platform for the regulation of IL-2 induced signals by GPI-proteins (e.g. CD48). Based on these data, the integrity of these GPI-microdomains seems critical in signal transduction through the IL-2R complex.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	European Journal Of Biochemistry. - 269 : 4 (2002), p. 1199-1208. -
További szerzők:	Dóczy-Bodnár Andrea (1970-) (biofizikus) Vereb György (1965-) (biofizikus, orvos) Bene László (1963-) (biofizikus) Vámosi György (1967-) (biofizikus) Szentesi Gergely (1976-) (kémia-fizika tanár) Szöllősi János (1953-) (biofizikus) Gáspár Rezső (1944-) (biofizikus) Horejsi, Václav Waldmann, Thomas A. Damjanovich Sándor (1936-2017) (biofizikus)
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001-es BibID:	BIBFORM005989
035-os BibID:	(scopus)0019558824
Első szerző:	Pozsgay Marianne
Cím:	Investigation of the substrate-binding site of trypsin by the aid of tripeptidyl-p-nitroanilide substrates / Marianne Pozsgay, Gábor Szabó, Sandor Bajusz, Roger Simonsson, Rezsö Gáspár, Pál Elődi
Dátum:	1981
Megjegyzések:	The kinetic parameters of the tryptic hydrolysis of tripeptidyl-p-nitroanilide substrates were determined and the data were studied by regression analysis. The sequence of substrates optimal from the viewpoint of kinetic constants 1/Km, kcat and kcat/Km was established and the influence of amino acid side chains on the binding and reactivity of substrates was calculated. At subsite P3 [notation of Schechter and Berger (1967) Biochem. Biophys, Res. Commun. 27, 157] polar side chains (Asn, D-Arg) are favourable as regards 1/Km, whereas hydrophobic side chains are preferred definitely from the viewpoint of catalytic efficiency, just as at subsite P2. In the side chain contributions, calculated for the kinetic parameters, the P3-S3 interaction predominates, in spite of the fact that the properties of the residue at subsite P1 decide whether hydrolysis occurs at all. The ZAsn-Ile-Arg-Nan sequence was predicted as a better substrate than those tested experimentally. The compound was synthesized, and the calculated value of its 1/Km (116.4 mM-1) was in a good agreement with the measured value (100.2 mM-1). Comparing the data obtained with trypsin with those observed with thrombin, elastase and subtilisin, we can establish that the homology of these enzymes can be characterized at each binding subsite by the aid of tripeptidyl-p-nitroanilide substrates. The quantities derived allow one to envisage a novel type of comparison of the proteases.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk analysis Anilides Animal Binding Sites Cattle enzymology Kinetics metabolism Pancreas Peptides Protein Binding Structure-Activity Relationship Substrate Specificity Support,Non-U.S.Gov't Trypsin
Megjelenés:	European Journal of Biochemistry. - 115 : 3 (1981), p. 497-502. -
További szerzők:	Szabó Gábor (1953-) (biofizikus) Bajusz Sándor Simonsson, Roger Gáspár Rezső (1944-) (biofizikus) Elődi Pál (1927-2002) (biokémikus)
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001-es BibID:	BIBFORM005988
Első szerző:	Pozsgay Marianne
Cím:	Study of the specificity of thrombin with tripeptidyl-p-nitroanilide substrates / Marianne Pozsgay, Gabriella Cs. Szabó, Pál Elődi, Rezsö Gáspár, Sandor Bajusz, Roger Simonsson
Dátum:	1981
Megjegyzések:	The kinetic behaviour of human thrombin has been studied with 26 tripeptidyl-p-nitroanilide substrates protected at the N terminus and with 9 unprotected ones. By the regression analysis of experimentally determined 1/Km, kcat and kcat/Km values the individual contribution of each side chain of the various substrates to the kinetic parameters was calculated. The contributions to the kinetic parameters of the best substrates provide information about the structure of the binding site. The interaction of subsites S1 and P1, which determines primary specificity, proved to be marginal on the basis of contribution values, though it depends upon this contact whether the substrate is hydrolyzed at all. At subsite S2 proline appeared to be favourable. Subsite S3 plays an important role in efficiency. The best parameters were obtained here with the D configurations of bulky amino acid residues. The aromatic protecting groups applied did not improve the properties of substrates. BZDPhe-Pro-Arg-Nan was predicted by calculation to be better than the protected substrates assayed. The compound was synthesized and tested. Its experimentally determined 1/Km, 55.1 mM-1, was in good agreement with 50.9 mM-1 found by calculation.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban analysis Anilides Human Kinetics metabolism Peptides Structure-Activity Relationship Substrate Specificity Support,Non-U.S.Gov't Thrombin
Megjelenés:	European Journal of Biochemistry. - 115 : 3 (1981), p. 491-495. -
További szerzők:	Szabó Cs. Gabriella Elődi Pál (1927-2002) (biokémikus) Gáspár Rezső (1944-) (biofizikus) Bajusz Sándor Simonsson, Roger
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001-es BibID:	BIBFORM005947
Első szerző:	Pozsgay Marianne
Cím:	A method for designing peptide substrates for proteases. Tripeptidyl-p-nitroanilide substrates for subtilisin Carlsberg / Pozsgay, M., Gaspar, R., Bajusz, S., Elodi, P.
Dátum:	1979
Megjegyzések:	The kinetic parameters of 25 peptidyl-p-nitroanilide substrates were investigated with subtilisin Carlsberg as model enzyme. 2. For a series of 12 substrates, the contribution of various side chains to the affinity constant was computed by regression analysis. From these contributions the sequence of a new and better substrate, N-benzyloxycarbonyl-arginyl-norleucyl-norleucyl-p-nitroanilide (Z-Arg-Nle-Nle-Nan) was predicted. The compound was synthesized and assayed. Its calculated 1/Km value, 43.5 mM-1, was in a good agreement with the value of 40.0 mM-1 that was determined experimentally. 3. On expanding the series to 19 substrates, it was found that the productivity of enzyme-substrate binding is influenced primarily by those subsites which have a significantly greater contribution to the affinity constants than others. 4. The additivity principle applied reasonably well for the contribution of individual side chains to the kinetic parameters. This fact suggests that regression analysis can be used for the prediction of the amino acid sequence of better substrates than those already tested, probably not only for subtilisin but also for other proteolytic enzymes
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Amino Acid Sequence analysis Kinetics metabolism Oligopeptides Regression Analysis Substrate Specificity Subtilisins
Megjelenés:	European Journal of Biochemistry. - 95 : 1 (1979), p. 115-119. -
További szerzők:	Gáspár Rezső (1944-) (biofizikus) Bajusz Sándor Elődi Pál (1927-2002) (biokémikus)
Internet cím:	elektronikus változat
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