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G Etzold

Publications and source records attributed to G Etzold.

At least 19 recordsLinked to original sources
PubMed1988

Manual N-terminal microsequencing of proteins electroeluted from polyacrylamide gel slices.

A simple and rapid procedure for preparation of proteins for manual microsequencing using sodium dodecyl sulfate gel electrophoresis is described. The procedure involves pre-electrophoretic labeling of the protein amino groups with a coloured Edman reagent, disk electrophoresis for purification or fractionation of the proteins, and reversed electrophoretic transfer of the separated protein from gel slices into a small volume of buffer (100 to 150 microliter) using a discontinuous conductivity gradient to recover the proteins. The pre-electrophoretic labeling facilitates location of the separated proteins in the gel and the monitoring of their complete electroelution. The isolated proteins are separated from excess of salts by acetone precipitation and solvent partitioning in pyridine/water (1:1) and subjected to manual DABITC/PITC degradation.

Amino Acid Sequence↗
PubMed1987

Identification of a polypeptide growth inhibitor from bovine mammary gland. Sequence homology to fatty acid- and retinoid-binding proteins.

A polypeptide growth inhibitor purified from bovine mammary gland (mammary-derived growth inhibitor) has been shown to reversibly inhibit proliferation of mammary carcinoma cells at concentrations of about 10(-10) M. The carrier of inhibitory activity has been identified biochemically as an about 13-kDa polypeptide and chemically by elucidating the amino acid sequence. No homology to any of the hitherto structurally investigated growth inhibitors (transforming growth factor beta, interferons) has been observed. The data revealed extensive sequence homology of mammary-derived growth inhibitor to a family of low molecular mass hydrophobic ligand-binding proteins, among them a fatty acid-binding protein from rat heart, myelin P2, a differentiation associated protein in adipocytes (p422) and the cellular retinoic acid-binding protein. Interaction with as yet unknown hydrophobic ligands might play a functional role in the mechanism of growth inhibition excerted by mammary-derived growth inhibitor.

Animals↗
PubMed1982

Carp insulin: amino acid sequence, biological activity and structural properties.

The amino acid sequence of insulin of carp (Cyprinus carpio) has been determined and correlated with its biological activity in a fat-cell test and its structural properties as measured by circular dichroism and sedimentation analysis. The amino acid sequence of carp insulin displays some unusual features: the B chain is longer at the N terminus by two residues as compared with mammalian insulins and there are substitutions of the charged residues, found in most insulins at positions B21 and B22, by proline and threonine respectively. On the other hand, all amino acid residues essential for biological activity and for the association of insulin monomers are the same in carp insulin. Accordingly, the half-maximal response in a fat-cell test is reached with carp insulin at concentrations which are only three times higher than with porcine insulin and the maximal response is the same. The circular dichroism spectrum of carp insulin resembles greatly that of bovine insulin indicating that it has a similar spatial structure. Despite amino acid substitutions in the dimer-dimer contact region, carp insulin is able to form hexamers.

Adipose Tissue↗
PubMed1981

Action of rat liver cathepsin L on glucagon.

The proteolytic specificity of cathepsin L on glucagon was determined. Major cleavages are found between Thr7 and Ser8, Asp15 and Ser16, and between Met27 and Asn28. The bonds Ser11-Lys12, Val23-Gln24, and Gln24-Trp25 are hydrolyzed to a relatively low extent only. Whereas cathepsin B hydroxyzes glucagon at the C-terminus by a peptidyldipeptidase mechanism, cathepsin L cleaves the same substrate clearly as endopeptidase.

Animals↗
PubMed1975

A facile synthesis of 5-(perfluoroalkyl)-pyrimidines.

In the paper a synthetic two stage procedure is described for the preparation of perfluoroalkylated derivatives of uracil and its nucleosides. Using copper bronze a perfluoroalkyl-copper-complex is formed from perfluoralkyl iodides in polar aprotic solvents, such as DMSO, and under inert conditions. The reaction of this complex with uracil, uridine and 2-deoxyuridine leads to the corresponding 5-substituted perfluoralkyl derivatives. It is shown by mass spectra that the substitution always takes place at the 5-position of the pyrimidine. The chemical and physical properties of the formed compounds are described.

Deoxyuridine↗