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Biomedical subjects

A Cooper

Publications and source records attributed to A Cooper.

At least 343 records · Page 19Linked to original sources
PubMed1970

Thermodynamic studies of the assembly in vitro of native collagen fibrils.

Measurements of the solubility of calf-skin tropocollagen in neutral phosphate buffers in the temperature range 20-37 degrees C show that native collagen fibril formation is an endothermic process made thermodynamically favourable by a large positive entropy of precipitation associated with structural changes in the surrounding solvent. The effect of inorganic ions and small solute molecules on precipitation seems to be correlated with their structural effects on liquid water. Heterogeneity in the precipitation properties of the collagen solutions may be related to changes in the configurational entropy of the macromolecules due to intramolecular cross-linking.

Bromides↗
PubMed1969

The precipitation of toroidal collagen fibrils.

The morphology of aggregates of calf-skin tropocollagen, precipitated by continuous injection into neutral phosphate buffers at 35 degrees , has been studied by electron microscopy. Although most of the collagen is precipitated as normal native fibrils, a small proportion forms closed toroidal structures having the usual native band-interband pattern. Theoretical considerations, based on elastic energies in a general microfibril model, predict that the toroids should have a simple super-helical structure, and this is not inconsistent with the observations. From the theoretical energies it was possible to estimate a crude lower limit of 3kcal./mole for the free energy of association of the tropocollagen macromolecules.

Animals↗