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1

Conformational studies of tachykinin peptides using NMR spectroscopy

100%

Rodziewicz S. , Xiao-Fei Q. , Rolka K.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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1998

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tom Vol. 2, No 1

47-53

EN

Conformational analysis of two tachykinin family peptides: Scyliorhinin I (ScyI) and Scyliorhinin II (ScyII) was carried out by 1D- and 2D-NMR (DQF-COSY, TOCSY, HMQC, HMBC, NOESY and ROESY) and molecular dynamics calculation methods in water and DMSO. Scyliorhinin I is an equipotent agonist of NK-1 and NK-2 tachykinin receptors and Scyliorhinin II is a selective agonist of the NK-3 tachykinin receptor. In DMSO, two groups of conformations (major and minor) were obtained for both peptides based on the experimental data. The conformations proposed for ScyI represent a folded structure, which show certain similarities to the structures reported for other NK-1 and NK-2 tachykinin agonists. In water ScyII displays a flexible, extended structure, whereas in DMSO the structure is more compact and in the fragment from the centre to the C-terminus several beta -turns may be present.

2

Analogue of Cucurbita maxima trypsin inhibitor III (CMTI-III) with AII L-cysteine residues substituted by L-penicillamine (Pen). Synthesis and evaluation of trypsin inhibitory activity

88%

Jaśkiewicz A. , Lesner A. , Różycki J. , Kupryszewski G. , Rolka K.

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tom Vol. 72, nr 12

2537-2540

EN

A 29-peptide, [ Pen(3,10,16,20,22,28) ] CMTI-III, an analogue of Cucurbita maxima trypsin inhibitor from squash seeds was synthesized by the solid phase method using the Fmoc chemistry. The inhibitory activity of the analogue, as measured by the association equilibrium constant (K-a) with bovine beta-trypsin, is of the same order of magnitude as that for the wild CMTI-III.

3

Low Molecular Mass Inhibitors of Bovine beta-Trypsin Containing Binding Loop Fragment of CMTI-III. Synthesis and Evaluation of Inhibitory Activity

75%

Frąszczak P. , Lis K. , Jaśkiewicz A. , Miecznikowska H. , Rolka K. , Kupryszewski G.

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tom Vol. 75, nr 12

1863-1868

EN

Three peptides with sequences related to the binding loop of Cucurbita maxima trypsin inhibitor III were obtained: [G3,GIO]CMTI-HI (1-10) (1), [A1,G3,A9,G10]MTlII (1-10) (2) and c(K-A-A-P-R-I-L-M-K-Y-A-E) (3). All peptides were synthesized by the solid-phase methodusing the Fmoc/Bu t procedure. Peptide 1 revealed a relatively high inhibitory activity (association equilibrium constant with bovine beta-trypsin Ka = 4 x 10 9 [M -1]). Significantly lower activity (Ka = 3.6x l O4 [M -1) was obtained for peptide 3. Peptide 2 appeared to be inactive.

4

Analogues of Ecballium elaterium Trypsin Inhibitor II (EETI-II) with L-Cysteine Residues Substituted by L-Penicillamine (Pen) and L-Homocysteine (Hcy) in Positions 19, 21 and 27

75%

Frąszczak P. , Kaźmierczak K. , Stawikowski M. , Jaśkiewicz A. , Kupryszewski G. , Rolka K.

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2002

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tom Vol. 76 / nr 10

1441-1446

EN

Two analogues of peptidic trypsin inhibitor isolated from seeds of Ecballium elaterium (EETI-II): [Pen19,21,27] EETI-II (1) and [Hcy19,21,27] EETI-II (2) were synthesized by the solid-phase method using the Fmoc/But procedure. Their inhibitory activity was determined by the calculation of association equilibrium constants (Ka) with bovine _-trypsin. In comparison with the parent compound, both analogues showed reduced trypsin inhibitory activity more than 7 and 18 times, respectively. We postulate that the observed differences may reflect the role of disulfide bridges in the interaction of inhibitors with trypsin or the introduced modifications change the conformational equilibrium of the analogues synthesized towards conformation(s) less favorable for the interaction with the enzyme.

5

The prion peptide forms ion channels in planar lipid bilayers

75%

Berest V. , Rutkowski M. , Rolka K. , Legowska A. , Debska G. , Stepkowski D. , Szewczyk A.

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2003

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tom 08

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nr 2

EN

One of the hypotheses concerning the pathogenic properties of the prion protein, considers its influence on cellular ion homeostasis. Using the lipid bilayer technique, the influence of prion-derived peptides on the lipid bilayer conductance was characterized. To evaluate the physiological significance and possible pathological functions of the peptides, their effect on the membrane potential and respiration rate of hippocampal mitochondria was also studied. We used a peptide bearing the human prion protein sequence YSNQNNF (PrP [169- 175]), and peptide SSQNNF (PrP [170-175]) bearing a naturally-occurring mutation in position 171 [N→S] linked to schizoaffective diseases in humans (Samaia, H.B., Mari, J.J., Vallada, H.P., Moura R.P., Simpson A.J.G., Brentani R.R. A prion-linked psychiatric disorder. Nature 390 (1997) 241). In this report, we show that PrP [170-175] N171S increases the conductance of planar lipid bilayers. Based on the conductance of single channel currents recorded in 500/500 mM KCl (cis/trans), we found a single channel conductance of 8 to 26 pS. The native prion peptide PrP [169-175] does not form ion channels in the lipid bilayer. Neither of the peptides significantly changed the membrane potential or respiration rate of isolated rat hippocampal mitochondria. We propose a possible mechanism for channel formation by aggregation of the prion-derived peptide.

6

Cztery pory roku w Zawadzkiem

75%

Rabicka M. , Kurczyk T. , Rolka K.

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2006

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nr 04

18-19

7

Cyclic analogues of proline-rich protein fragments. Part 1. Synthesis and evaluation of immunotropic activity

63%

Wirkus-Romanowska I. , Ciurak M. , Miecznikowska H. , Rolka K. , Janusz M. , Szymaniec S. , Krukowska K. , Lisowski J. , Kupryszewski G.

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tom Vol. 72, nr 11

2394-2398

EN

Proline-rich protein (PRP), isolated from ovine colostrum, possesses strong immunotropic activity. The nonapeptide (Val-Glu-Ser-Tyr-Val-Pro-Leu-Phe-Pro) and the hexapeptide (Tyr-Val-Pro-Leu-Phe-Pro) PRP fragments reveled biological activity similar to that of the native protein. Seeking for analogues of PRP fragments with costrained structure, two cyclic peptides were synthesized by the solid phase method: Cys-Val-Glu-Ser-Tyr-Val-Pro-Leu-Phe-Pro-Cys and Ac-Glu-Tyr-Val-Pro-Leu-Phe-Pro-Lys-NH2. Immunotropic activity of both peptides in murine system was the same as for linear nonapeptide, whereas all three peptides were practically inactive in human system, where resistance to hydrocortisone and induction of two cytokinins IFN and TNF were used as indicators, respectively.