Biomedical subjects
Publications and source records attributed to G D Rose.
Peptide chain turns are those parts of a globular protein where the backbone changes its direction. A simple, non-empirical hypothesis is presented to account for both the turns and the hydrophobic core of the protein using only the amino acid sequence.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Twelve globular proteins have been examined to test whether structural segments are oriented at random. Structural segments are defined as the primary sequence of linear chain neighbors bounded by consecutive peptide chain turns. It is shown that, with this definition, a structural segment can be well approximated by a straight-line segment. Each protein in the test set was exhaustively partitioned into its constituent structural segments, and a method is presented for comparing pairwise intersegment orientations. Within a protein, it is found that three-dimensionally close-segments exhibit a pronounced tendency toward parallel orientation while distant segments are randomly oriented. Finally, some conclusions are presented relating to the general problem of segment packing in globular proteins.
Explore the source record for details and available documents.
Reverse turns are specific sites in proteins at which the polypeptide chain changes its overall direction. This category of secondary structure enables the chain to turn a corner, and its frequent occurrence is the geometric basis for the ultimate globular shape of the protein. beta-Turns in particular are comprised of four consecutive residues with a stereochemistry that constrains the turn to be polar. In consequence, turns are almost always situated at the surface of the protein, in contact with solvent water. We have searched proteins of known structure and find that, on occasion, a turn may be buried within the hydrophobic interior of the molecule. In every instance of a buried turn, one or more solvent molecules were also found in a hydrogen-bonded complex with main-chain atoms of the turn residues. These bound water molecules appear to function as an integral part of the protein structure.