Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 7

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

The investigation of [(4'-amino)-Phe]^4-enkephalin conformation in water by the spectrofluorimetric procedure

100%
Jankowski A., Siemion I. Z., Szewczuk Z.
Acta Biochimica Polonica
|
1981
|
vol. 28
|
issue 1
11-20
2
Content available remote

Conformational stability of six truncated cHMG1a proteins studied in their mixture by H/D exchange and electrospray ionization mass spectrometry.

100%
Petry I., Wiśniewski J. R., Szewczuk Z.
Acta Biochimica Polonica
|
2001
|
vol. 48
|
issue 4
1131-1136
EN
The high mobility group (HMG) proteins are abundant non-histone components of eukaryotic chromatin. The presence of C-terminal acidic tails is a common feature of the majority of HMG proteins. Although the biological significance of the acidic domains is not clear, they are conferring conformational and metabolic stability to the proteins in vitro. Moreover, the length and net charge of the acidic tails affect the strength of HMG protein interaction with DNA. Synthesis of an insect HMG protein by standard recombinant technology in bacteria leads to a mixture of the intact protein (cHMG1a-(1-113) (I)) and a series of its degradation products truncated at the C tail: cHMG1a-(1-111) (II); cHMG1a-(1-110) (III); cHMG1a-(1-109) (IV); cHMG1a-(1-108) (V); cHMG1a-(1-107) (VI); cHMG1a-(1-106) (VII). The proteins differ from each other only by the number of amino-acid residues at the C-terminal tail. We used H/D exchange mass spectrometry to characterize the stability of the proteins directly in their mixture. The results show that the proteins I-V and VII have very similar conformations. The protein VI is less compact and exchanges its protons faster than the others. It may be concluded that the C-terminal tail influences the conformation of the cHMG1a protein and that individual residues in this part of the protein play a key role in its compactness.
3
Content available remote

The determination of thymopoietin conformation based on X-ray structure of a discontinuous thymopoietin-like motif of G-actin

100%
Siemion I. Z., Strug I., Szewczuk Z.
Acta Biochimica Polonica
|
1997
|
vol. 44
|
issue 3
519-525
4
Content available remote

Design, synthesis and biological evaluation of a new bridged immunosuppressor.

88%
Szewczuk Z., Wilczyński A., Petry I., Siemion I. Z., Wieczorek Z.
Acta Biochimica Polonica
|
2001
|
vol. 48
|
issue 4
1147-1150
EN
A bridged peptide with the sequence: H-Thr-Pro-Gln-Arg-Gly-Asp-Val-γ-Abu-Asn-Asp-Gln-Glu-Glu-Thr-Thr-Gly-Val-Val-Ser-Thr-Pro-Leu-Ile-Arg-Asn-Gly-OH was designed to mimic the discontinuous epitope of the HLA-DQ molecule that might interact with CD4. The bridged peptide revealed distinct suppressory effect in the humoral immune response. This result supports our suggestion that the 164-172 region of the HLA-DQ molecule may enhance its interactions with coreceptors, possibly with CD4.
5
Content available remote

Evaluation of high temperature glycation of proteins and peptides by electrospray ionization mass spectrometry.

88%
Stefanowicz P., Boratyński J., Kańska U., Petry I., Szewczuk Z.
Acta Biochimica Polonica
|
2001
|
vol. 48
|
issue 4
1137-1141
EN
Recently Boratyński & Roy (Glycoconjugate J., 1998, 15, 131) described a fast and convenient procedure for the synthesis of glycoconjugates. In the present study we used ESI-MS and circular dichroism as tools to analyze non-enzymatic glycation prod- ucts of proteins and peptides. We discuss influence of reaction conditions on the rate of glycation of lysozyme. We analyze for the first time collision induced dissociation spectra of the obtained peptide conjugates.
6
Content available remote

Immunosuppressory activity of the cyclodimeric peptide with RGD-sequences.

76%
Szewczuk Z., Buczek P., Stefanowicz P., Krajewski K., Wieczore Z., Siemion I. Z.
Acta Biochimica Polonica
|
2001
|
vol. 48
|
issue 1
121-130
EN
Our previous studies showed that the nonapeptide fragment of HLA-DQ of the sequence H-Thr-Pro-Gln-Arg-Gly-Asp-Val-Tyr-Thr-OH, located in the β164-172 loop, strongly suppresses the humoral and cellular immune responses, while its shorter analogs, H-Arg-Gly-Asp-Val-OH, H-Arg-Gly-Asp-Val-Tyr-OH and H-Gln-Arg-Gly-Asp-Val-Tyr-OH show only a weak stimulatory activity in respect to the humoral immunological response. These fragments contain the Arg-Gly-Asp (RGD) sequence, known for its importance for cellular association phenomena. Based on the crystal structure of HLA-DR1, we also designed and synthesized a cyclic analog H-Cys-Arg-Gly-Asp-Val-Tyr-Cys-OH with restricted conformation, which strongly suppresses the immune response and selectively inhibits the αvβ3 integrin, suggesting that the mechanism of the immunosuppressory action of the peptide is associated with inhibition of the integrin. In this paper we present the design and synthesis of the cyclodimeric peptide, Arg-Gly-Asp-Arg-Gly-Asp, which is also known as a selective αvβ3 inhibitor. The synthesized peptide strongly suppresses both the humoral and cellular immune response. The results support our hypothesis that the immunomodulatory activity of HLA-DQ fragments may be connected with their interactions with some particular integrins on the cell surface.
7
Content available remote

Hydrate of 2,3:4,5-di-O-isopropylidene-β-D-arabino-hexos-2-ulo-2,6-pyranose as new crystalline reagent in the preparation of Amadori derived peptides

76%
Stefanowicz P., Batorska J., Kijewska M., Bartosz-Bechowski H., Szewczuk Z., Lis T.
Open Chemistry
|
2010
|
vol. 8
|
issue 1
28-33
EN
We established, that crystalline hydrate of 2,3:4,5-di-O-isopropylidene-β-D-arabino-hexos-2-ulo-2,6-pyranose is a new, convenient and stable reagent for solid phase synthesis of peptide derived Amadori products. The structure of the title compound was studied by X-ray analysis, NMR spectroscopy, and high resolution ESI-MS. The crystal structure indicated the existence of two symmetry-independent molecules that were not connected with hydrogen bonds. A comparison with previously reported 2,3:4,5-di-O-isopropylidene-β-D-fructopyranose revealed, that these two compounds are isostructural. [...]
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.