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Biomedical subjects

D Hermann

Publications and source records attributed to D Hermann.

47 records · Page 3Linked to original sources
PubMed1983

Interferon induction by platinum(II)-poly(I).poly(C) complexes.

The effect of the interaction between poly(I).poly(C) and cis-dichloro-diammineplatinum(II) (cis-Pt), its trans analogue and chloro-diethylene-triamminoplatinum(II) (dien-Pt) on interferon induction activity was investigated. The covalent monodentate fixation of the three compounds on N7 of inosine has different effects on the structure and thermostability of poly(I). poly(C) which is well reflected by the interferon induction activity of the samples. Thus, the sandwich stabilization by dien-Pt at low binding ratios is manifested by an increased interferon induction and a high resistance towards RNAase degradation. The destabilization of the duplex by cis-Pt decreases interferon induction, accompanied by an increase in RNAase sensitivity of the complexes. In the case of trans-Pt the duplex structure is little perturbed and interferon induction is essentially maintained.

Animals↗
PubMed1979

Dissociation of double-stranded poly(I) . poly(C) by cis-diammine-dichloro-Pt(II).

The covalent binding of cis-Pt(NH3)2Cl2 on the double stranded poly(I) . poly(C) induced an irreversible dissociation of the two strands. This dissociation was evidenced mainly by poly(I)-Agarose affinity chromatography which allowed to recover free strands of cis-Pt(NH3)2Cl2-poly(I) from a cis-Pt(NH3)2Cl2-poly(I) . poly(C) complex, by density equilibrium centrifugation where free poly(C) could be isolated, and by acid titrations of the metal-poly(I) . poly(C) complexes. The separation of the two strands of the polyribonucleotide upon cis-Pt(NH3)2Cl2 fixation was shown not to exceed 90--95%. A dissociation curve of the polynucleotide double helix as a function of the amount of bound cis-Pt(NH3)2Cl2 was determined and was shown to be of a characteristic cooperative effect. The fixation of the paltinum compound to poly(I) . poly(C) seemed also to be cooperative.

Chemical Phenomena↗
PubMed1977

Chromatin very small angle neutron scattering: further evidence for a 30 nm diameter super coil in dilute solutions.

Intact chromatin, chromatin minus histone H1, and nuclease digestion fragments have been studied by very small angle neutron scattering. The results are not consistent with a straight chain of nucleosomes and require the presence of a higher order coiling in monovalent salt solutions. The data are interpretable by a structure having a cross section radius of gryration of 8.5 +/- 1 nm, which suggests an outer diameter for a coil of nucleosomes of 27 +/- 3 nm.

Animals↗