Biomedical subjects

M Smoluch

Publications and source records attributed to M Smoluch.

6 recordsLinked to original sources

PubMed2004

Temperature dependence of the melittin folding equilibrium studied by means of fluorescence excitation spectra.

The temperature dependence of fluorescence excitation spectra is investigated. This gives information on melittin folding equilibrium complementary to that obtained from fluorescence emission studies. A fit of the excitation spectra of melittin with three Gaussian functions gives good results. It suggests that in melittin a reversal of La and Lb electronic states of tryptophane takes place. The separate La and Lb bands exhibit a temperature dependence of the width and maximum.

Melitten↗

PubMed2001

Tryptic hydrolysis of hGH-RH(1-29)-NH2 analogues containing Lys or Orn in positions 12 and 21.

Two analogues of the 29 amino acid sequence of human growth hormone-releasing hormone, namely [Nle27]hGH-RH(1-29)-NH2 and [Orn(12,21),Nle27]hGH-RH(1-29)-NH2, have been synthesized and subjected to digestion by trypsin. The course of degradation was followed using RP-HPLC and ESI-MS. Several intermediates and final products of degradation were identified and conclusions regarding the rate of cleavages at different positions occupied by Lys and Arg residues were drawn. The analogue containing ornithine was found to be less susceptible to hydrolysis by trypsin: the 12-13 and 21-22 peptide bonds were completely resistant to the cleavage. The results show that by replacing Lys with Orn, a possibility exists to design new peptides, which could be more stable in biological fluids.

Amino Acid Sequence↗

PubMed2001

Copper(II)-lincomycin: complexation pattern and oxidative activity.

Coordination of Cu(II) to lincomycin was studied by potentiometry, UV-Vis, circular dichroism (CD), EPR, NMR, cyclic voltammetry (CV) and ESI-MS. Only mononuclear complexes of stoichiometries ranging from CuL to CuH(-3)L were found. In the main species present at neutral pH, CuH(-2)L, lincomycin bonds Cu(II) through both of its nitrogen donors, and a deprotonated oxygen donor at C4 of the sugar moiety. High pressure liquid chromatography (HPLC) of products of 2'-deoxyguanosine (dG) oxidation and agarose gel electrophoresis of plasmid DNA confirmed that lincomycin complexes effectively facilitate dG oxidation by H2O2, but are not able to cleave double-stranded plasmid DNA.

Anti-Bacterial Agents↗

PubMed2001

Arginine-specific cysteine proteinase from porphyromonas gingivalis as a convenient tool in protein chemistry.

RgpB, a cysteine proteinase produced by Porphyromonas gingivalis, exhibits proteolytic activity selectively directed against peptide bonds containing an arginine residue in the P1 position. Here we show that this enzyme can be used for very efficient and specific protein cleavage. RgpB is highly active even at high concentrations of denaturing agents, including urea (up to 6 M) and SDS (0.1%), both of them being commonly used for solubilization of insoluble proteins and peptides. Moreover, RgpB is able to digest polypeptide chains in buffers supplemented with 1% Triton X-100, 1% octyl or decylpyranoside, detergents employed for the enzymatic digestion of proteins transferred onto nitrocellulose membranes. These features render RgpB a suitable tool for use in protein chemistry.

Amino Acid Sequence↗

PubMed2001

Search for new synthetic immunosuppressants II. Tetrazole analogues of hymenistatin I.

Linear and cyclic hymenistatin I (HS I) analogues with dipeptide segments Ile2-Pro3 Pro3-Pro4 and Val6-Pro7 replaced by their tetrazole analogues Ile2-psi[CN4]-Ala3', Pro3-psi[CN4]-Ala4 and Val6-psi[CN4]-Ala7 were synthesized by the solid phase peptide synthesis method and cyclized with the TBTU and/or HATU reagent. The peptides were examined for their immunosuppressive activity in the lymphocyte proliferation test (LPT).

Amino Acid Sequence↗

PubMed2000

Determination of nociceptin-orphanin FQ metabolites by capillary LC-MS.

Nociceptin-orphanin FQ (OFQ/N) is a newly discovered peptide involved in pain transmission. The method is described to identify metabolic pathway of this neuropeptide in the spinal cord of rats using capillary size-exclusion liquid chromatography coupled to electrospray ionization mass spectrometry. The applied technique is rapid and selective, and allows for simultaneous measurement and quantitation of several fragments in the incubation mixture.

Animals↗