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Biomedical subjects

B Lotz

Publications and source records attributed to B Lotz.

28 records · Page 2Linked to original sources
PubMed1976

[Enzyme induction in Streptomyces hydrogenans, VI. Studies on the induction of 20beta-hydroxysteroid dehydrogenase, using immunological methods].

Antiserum against crystallized 20beta-hydroxysteroid dehydrogenase from Streptomyces hydrogenans was used for various immunodiffusion and immunoprecipitation tests to show an increase of the de novo synthesis of 20beta-hydroxysteroid dehydrogenase by Streptomyces hydrogenans after cultivation of the cells in the presence of 11beta,21-dihydroxy-4,17(20)-pregnadien-3-one. Half lives of mRNA for 20beta-hydroxysteroid dehydrogenase in induced cells and of total mRNA in non-induced cells were calculated to be 126 s and 66 s, respectively. In vivo, 20beta-hydroxysteroid dehydrogenase appears to consist of four equal subunits. The monomers, molecular weight of 27 300, show a high tendency to form dimers and tetramers in the absence of dissociating agents. The aggregation is completely reversible in the presence of increasing concentrations of sodium dodecylsulfate.

Animals↗
PubMedDate not supplied

Helical structures of poly(D-L-peptides). A conformational energy analysis.

Conformational energy calculations are reported for a number of possible helical structures of poly(D-L-peptides): the alpha helix, two single-stranded piDL, and five double-stranded pipiDL helices. For a poly(D-alanine-L-alanine) sequence, the energies of the various helices are found to differ by less than 1 kcal/(mol residue). For some helices (especially the piDL ones) two structural variants are predicted. These variants, called "goniomers", are characterized by reversed sequences of conformational angles but have the same screw sense and similar helical parameters. A biological implication of these goniomers is suggested, and their usefulness as a critical test for energy calculations is considered.

Alanine↗
PubMedDate not supplied

Properties of an antiserum against Streptomyces hydrogenans 20beta-hydroxysteroid dehydrogenase.

Antiserum against crystallized 20beta-hydroxysteroid dehydrogenase from Streptomyces hydrogenans was used for different immunodiffusion and immunoprecipitation tests to quantify the bacterial enzyme in cell-free supernatants of the microorganism. After immunoprecipitation and gel electrophoresis the molecular weight of the subunits of 20beta-hydroxysteroid dehydrogenase was calculated to be 27 300 +/- 700.

Antigen-Antibody Complex↗