Biomedical subjects

Jolanta Sereikaite

Publications and source records attributed to Jolanta Sereikaite.

5 recordsLinked to original sources

PubMed2006

Production of recombinant mink growth hormone in E. coli.

Escherichia coli cells expressing mink (Mustela vison) growth hormone were grown in a batch fermentation process. The expression level was estimated to be 27% of the total cellular protein after 3 h of induction with 1 mM isopropyl beta-D-thiogalactoside (IPTG). If the expression of mink growth hormone (mGH) was induced with 0.2 mM IPTG, the concentration of target protein was slightly lower and was found to be 23% at the same time after induction. mGH expressed as inclusion bodies was solubilized in 8 M urea and renatured by dilution protocol at a protein concentration of 1.4-2.1 mg/ml in the presence of glutathione pair in a final concentration of 11.3 mM. [GSH]/[GSSG] ratio equal to 2/1 was used. Two-step purification process comprising of ion-exchange chromatography on Q-Sepharose and hydrophobic chromatography on Phenyl-Sepharose was developed. Some 25-30 mg of highly purified and biologically active mGH was obtained from 4 g of biomass. The method presented in this study allows producing large quantities of mGH and considering initiation of scientific investigation on mGH effect on mink in vivo and availability in fur industry.

Animals↗

PubMed2006

Examination of dye-protein interaction by gel-permeation chromatography.

The interaction of Cibacron blue F3G-A with two therapeutic proteins, recombinant human growth hormone and recombinant human interferon-alpha2b, has been examined by applying gel-permeation chromatography in combination with the absorption difference spectroscopy. The complexes of these proteins with Cibacron blue F3G-A have been isolated, and their absorbance spectra have been registered. The influence of Cibacron blue F3G-A on the oligomeric state of proteins has been investigated. It was found that Cibacron blue F3G-A promotes the generation of interferon-alpha2b dimers at pH 5.0.

Chromatography, Gel↗

PubMed2006

Protein scission by metal ion-ascorbate system.

About 14 proteins were tested for specific oxidative scission catalyzed by metal ions in the presence of ascorbate and oxidizing agents (O(2) or hydrogen peroxide). Only four of them were degraded by Fe(3+)/Fe(2+)- ascorbate, twelve - by Cu(2+)/Cu(+)-ascorbate and two proteins (alpha- and beta-caseins) were degraded by Pd(2+) ions. The rate and the intensity of degradation are very different for various proteins. For the most of tested proteins only a small fraction of molecules was degraded. None of them was degraded completely. Two possible reasons of protein stability against oxidative degradation may be proposed as follows: either there is no metal binding site in a protein molecule, or metal binding ligands of protein undergo a rapid oxidative modification and the metal ion is released from the binding site. Human growth hormone was cut specifically at two sites by Cu(2+)/Cu(+)-ascorbate system. At least one of amino acid residues of this protein was modified by formation of reactive carbonyl.

Ascorbic Acid↗

PubMed2006

Congo red interaction with alpha-proteins.

The ability of Congo red to form complexes with alpha-proteins, human growth hormone and human interferon-alpha2b, was found by absorption difference spectroscopy. A human growth hormone-Congo red complex was isolated by gel-permeation chromatography, and its visible absorption spectrum was registered in comparison to free dye. The ability of Congo red to induce dimerization of human growth hormone was demonstrated using chemical cross-linking agents 1,3,5-triacryloyl-hexahydro-s-triazine and ethylene glycol bis(succinimidylsuccinate).

Biophysics↗

PubMedDate not supplied

Oligomeric assembly and ligand binding of the members of protein family YER057c/YIL051c/YJGF.

Proteins UK114 and p14.5 are both members of the putative family of small proteins YER057c/YIL051c/YjgF. The biological role of these proteins is not understood very well, and in addition, their oligomeric structure in solution remains controversial. We therefore investigated the oligomeric structure of UK114 and p14.5 using a number of methods. Both proteins have exhibited a homotrimeric structure in solution. Indeed the trimeric structure of the two proteins appeared to be so similar that when protein subunits derived from different species were mixed, stable heterotrimeric complexes (monomer ratio of 1:2 and 2:1 of UK114 and p14.5, respectively) could be formed in vitro. Furthermore, the trimeric structure of both UK114 and p14.5 proved essential for the stoichiometric hydrophobic ligand, such as fatty acid binding activity of the two proteins.

Anilino Naphthalenesulfonates↗