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Biomedical subjects

R Langridge

Publications and source records attributed to R Langridge.

At least 55 records · Page 3Linked to original sources
PubMed1982

Computer graphics in drug design: molecular modeling of thyroid hormone-prealbumin interactions.

Computer graphics modeling of the thyroxine-prealbumin complex provides a detailed picture of the interactions between thyroxine and prealbumin. A wide variety of thyroid hormone analogue-prealbumin complexes were modeled by calculating the molecular surfaces of the analogues and the prealbumin hormone-binding site. Analogues with high binding affinity were observed to fill more of the hormone-binding site than low-affinity analogues. These surface models described many aspects of the hormone-protein interaction which were not obvious using simple wire models and led us to develop a model which accounts for thyroid hormone-prealbumin structure-activity relationships and ultimately to predict and measure the relative binding affinities of four previously untested thyroid hormone analogues to prealbumin.

Chemical Phenomena↗
PubMed1982

Electrostatic potential molecular surfaces.

Color-coded computer graphics representations of the electrostatic potentials of trypsin, trypsin-inhibitor, prealbumin and its thyroxine complex, fragments of double-helical DNA, and a netropsin--DNA complex illustrate the electrostatic and topographic complementarity in macromolecule-ligand interactions. This approach is powerful in revealing intermolecular specificity and shows promise of having predictive value in drug design.

Computers↗
PubMed1981

Real-time color graphics in studies of molecular interactions.

Studies of the structures and interactions of large biological molecules require both coordinate data and three-dimensional visualization. Orthodox molecular models often bear a tenuous relationship to the coordinate data. In contrast, computer graphics requires that the display directly and accurately represent the data, and storage of modified configurations and recovery of original structures are simple. Software has been developed that allows real-time display of color line and surface displays of several interacting molecules, while quantitatively monitoring the stereochemistry.

Carboxypeptidases↗
PubMed1975

X-ray fiber diffraction evidence for neighbor exclusion binding of a platinum metallointercalation reagent to DNA.

Good quality x-ray diffraction patterns have been obtained of polycrystalline fibers containing 2-hydroxyethanethiolato(2,2'2"-terpyridine)platinum(II) bound to calf thymus DNA by intercalation. The photographs strongly support the neighbor exclusion binding model in which electron-dense platinum atoms are regularly distributed at 10.2 A intervals, every other interbase pair site.

Animals↗
PubMed1970

Sulfate-binding protein from Salmonella typhimurium: physical properties.

This protein binds sulfate strongly and is implicated in sulfate transport in Salmonella typhimurium. It has a molecular weight of 32,000 and an axial ratio of 4:1. Crystals are elongate prisms up to 0.5 millimeter. X-ray diffraction photographs give discrete crystalline reflections to a spacing of at least 2 angstroms. The unit cell is orthorhombic P2(1)2(1)2(1), with four molecules per unit cell of 40.8 by 47.5 by 136 angstroms. This is consistent with a highly asymmetric molecule such as the prolate ellipsoid suggested by the other physical measurements. Addition of sulfate had minimum effects on the physical properties as measured by light absorption, optical rotary dispersion, circular dichroism, fluorescence and its depolarization, nuclear magnetic resonance, and sedimentation velocity.

Bacterial Proteins↗