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D L Worcester

Publications and source records attributed to D L Worcester.

25 records · Page 2Linked to original sources
PubMed1977

The structure of the chromatin core particle in solution.

The shape and size of the nucleosomal core particle from chromatin has been examined by analysis of neutron and X-ray scattering data from dilute solutions. Calculations of scattering for many different models have been made and only one model was able to account for both the X-ray and neutron profiles. This model is an oblate structure with height about 50A and diameter 110A. The DNA is mainly confined to two annuli located at the top and bottom respectively of the core particle positioned on the outside of a compact protein core which has a height of about 40A and diameter about 73A.

Animals↗
PubMed1976

Neutron diffraction studies of biological membranes and membrane components.

In this paper the methods and techniques of neutron diffraction studies of biological membranes and membrane components have been described and demonstrated. Foremost among these are the methods of deuterium exchange and deuterium labeling, since they can directly provide locations of membrane components. In addition, the methods of contrast variation with H2O-D2O mixtures, swelling, direct scaling of data from deuterium-labeled structures, and magnetic orientation have provided useful information in neutron diffraction analyses of membrane structures. Although this field is only in its infancy, it clearly has very encouraging prospects.

Cell Membrane↗
PubMed1975

Low-angle neutron scattering from chromatin subunit particles.

Monomer chromatin particles containing 140 base pairs of DNA and eight histone molecules have been studied by neutron scattering. From measurements in various H2O/D2O mixtures, radii of gyration and the average scattering density of the particle were determined. The radius of gyration under conditions when scattering from the DNA dominates is 50A, and when scattering from the protein dominates, 30A. Consequently the core of the particle is largely occupied by the histones while the outer shell consists of DNA together with some of the histone.

Animals↗