title: A survey of x-ray diffraction studies of enzyme-other molecule interactions as possible models for receptor sites.
abstract: In the absence of a structure for a hormone-receptor complex, one may ask what systems of known structure are most likely to provide information about hormone interactions. Here, I discussed enzyme-substrate, enzyme-(protein) inhibitor, enzyme fragment (S peptide), and antibody-hapten (or antigen) interactions as possible models. Following a study of a fairly inflexible hormone (insulin) and of a flexible hormone (glucagon), I commented on probable binding regions. Finally, my conclusion was that, at present, allosteric enzymes have many of the characteristics thought to be present in those hormone-receptor interactions which activate enzymes. This model does not necessarily apply in detail to examples of hormone interactions that affect permeability of the cell wall or activate genetic processes.
mesh_terms: D000906:Antibodies / Q000378:metabolism; D001221:Aspartate Carbamoyltransferase / Q000378:metabolism; D004798:Enzymes / Q000378:metabolism*; D005934:Glucagon / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D008954:Models, Biological; D008958:Models, Molecular; D010446:Peptide Fragments; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012260:Ribonucleases / Q000378:metabolism; D013816:Thermodynamics; D014357:Trypsin / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D000906:Antibodies; D004798:Enzymes; D007328:Insulin; D010446:Peptide Fragments; D011956:Receptors, Cell Surface; C023560:ribonuclease S-peptide; D005934:Glucagon; D001221:Aspartate Carbamoyltransferase; D012260:Ribonucleases; D014357:Trypsin