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Biomedical subjects

G Damaschun

Publications and source records attributed to G Damaschun.

71 records · Page 4Linked to original sources
PubMed1976

Folding crystallization of DNA. Circular dichroism studies.

CD spectra of DNA monocrystals are extremely different from spectra of psi-DNA or DNA-histone H1 or DNA-polylysine complexes. They are discussed to be dependent on the supramolecular organization of DNA in the condensed form, and they are not in contradiction to the previously proposed seven folding model of DNA in chromatin. Conclusions are drawn with regard to the interpretation of chromatin CD spectra.

Chromatin↗
PubMed1975

[Structure of animal ribosomes. VI. Adynamic model of ribosome structure].

A dynamic model for the structure of ribosomes is developed using X-ray small-angle scattering data and electron micrographs of ribosomes and polysomes. The large subunit has the shape of a conical frustum, and has a groove at its flat side. The small subunit consists of two semiparticles which are connected by a molecular strand; it may assume two conformations: a prolate P conformation and an oblate O conformation. Translocation of the ribosome along the mRNA in the elongation process of protein synthesis is accomplished by cyclic conformation transitions P-O-P-O in combination with the linking and rupturing of bonds. This mechanism is called "rack and roll" mechanism.

Animals↗
PubMed1975

[The supramolecular organization of oxyhemoglobin in erythrocytes. A small-angle x-ray scattering study].

From X-ray scattering diagrams of concentrated solutions of hemoglobin the pair-correlation function of the molecules is calculated. At a concentration of 324 g/l the distance between neighbouring molecules amounts to 65 A. The number of direct neighbours of one molecule is 9. The pair-correlation function cannot be described by the assumption of a lattice-cell-model; therefore, a lattice-vacancy-model with fluid order is proposed.

Erythrocytes↗
PubMed1975

[Folding of deoxyribonucleic acid in chromatin].

A structural model for the folding of deoxyribonucleic acid (DNA) in chromatin has been evolved on the basis of the X-ray diffraction patterns of deoxyribonucleoproteids (DNP). The DNA is oriented in the direction of DNP fibres and does not exhibit a superhelical structure. In the nu-bodies the DNA is folded 7 times to and fro on the envelope of a cylinder 10 nm in diameter. The height of the DNA-hairpins is 9 nm - 10 nm. The spacing between the refolded DNA segments is 3,6 nm. This supramolecular folding crystalization of the DNA is a general principle of organization and, through different types of morphological growth of the folding crystals, leads to the chromatin, to psi-DNA, to DNA monocrystals, and to DNA packing in some phage heads.

Chromatin↗