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Biomedical subjects

Alois Jungbauer

Publications and source records attributed to Alois Jungbauer.

40 records · Page 3Linked to original sources
PubMed2002

Yeast reporter system for rapid determination of estrogenic activity.

An in vitro test system for the determination of estrogens, xeno- and phytoestrogens, based on the activation of human estrogen receptor-alpha, has been examined for ability in monitoring environmental estrogens. The system consists of an expression plasmid for the human estrogen receptor-alpha and a reporter plasmid containing the lacZ gene under the control of the vitellogenin hormone response element. These plasmids have been transformed into S. cerevisae. Cultivation of yeast in the presence of estrogenic substances leads to activation of the estrogen receptor and induces the expression of the reporter lacZ. beta-Galactosidase activity of the translated gene lacZ is a measure of the estrogenic activity of a compound. First, the selectivity of the system was compared to data available in the literature. Then the sensitivity of the system was checked. The detection limit is 0.1 ng 17-beta estradiol or an equivalent activity per liter, if a sample can be concentrated 1000-fold. The system has been further characterized by selected compounds with known and unknown estrogenic activity.

Amino Acid Sequence↗
PubMed2002

Recombinant autofluorescent landmarks for standardization of electrophoretic migration of proteins.

Unequivocal identification of unknown protein spot patterns in two-dimensional (2-D) electrophoresis still represents a major problem when performing comparative studies of different 2-D electrophoresis gels. Inhomogeneity of gels due to variations in the gel casting procedure, electroendoosmosis and heterogeneity of proteins are major contributions to variations in migration patterns. By fusing green fluorescent protein to a number of well-defined selected proteins (human lysozyme, initiation factor 5a (EIF5a), rapamycin-selective 25 kDa immunophilin (FKBP25), and heat shock protein 90 beta (hsp90)), the isoelectric points and the molecular mass were designed. Proteins were additionally tagged with the FLAG tag enabling rapid purification by immunoaffinity chromatography. The fusion proteins were expressed intracellularly in yeast to avoid heterogeneity caused by post-translational modifications. The quality and applicability was tested in 1-D and 2-D electrophoresis. Sharp bands or symmetric spots were obtained. The proteins are considered as a new generation of reference proteins for electrokinetic separation methods.

Blotting, Western↗
PubMedDate not supplied

Direct synthesis of peptides on convective interaction media monolithic columns for affinity chromatography.

Solid-phase peptide synthesis was performed on glycidyle methacrylate-co-ethylene dimethacrylate monoliths using Fmoc chemistry. The native epoxy groups were amino-functionalized by reaction with ethylenediamine or ammonia ions. A peptide directed against human blood coagulation factor VIII was synthesized as a model peptide. Amino acid analysis revealed the correct amino acid ratio as present in the sequence. The ligand density of 5 micromol/mL was equal to that achieved with conventional peptide immobilization via epoxy groups. These supports were directly used as peptide affinity chromatography matrixes. The functionality of the CIM monolithic supports was proven by affinity chromatography of factor VIII. The ammonia-functionalized support performed with low hydrophobicity and did not show unspecific adsorption of proteins.

Adsorption↗