Department of Medicine, University of California, La Jolla.
We have demonstrated two heat shock proteins (HSP's) in the human placenta that specifically bind calcitonin. Binding specificity was shown by ligand-affinity chromatography and by competitive binding studies. The HSP's were identified by Western analysis and by amino acid sequence. Our observations are consistent with the hypothesis that HSP's may function by binding and interacting with cellular proteins and peptides during their biogenesis. This interaction may both depend upon and produce conformational changes in these ligands during their intracellular processing. Additionally, HSP-peptide hormone interactions may confound studies designed to investigate classical receptor-hormone interactions.