title: The interaction of melittin with calmodulin and its tryptic fragments.
abstract: Melittin has been found to interact with both the N- and C-terminal half-molecules of calmodulin, as well as the intact molecule, in the presence of Ca2+. The interaction results in a major change in the microenvironment of Trp-19, which is in a more nonpolar, solvent-shielded, and immobilized microenvironment in the complex. The properties of Tyr-99 and Tyr-138 of calmodulin are altered by complex formation. From measurements of the efficiencies of radiationless energy transfer from Trp-19 to the nitro derivatives of Tyr-99 and/or Tyr-138, it is concluded that Trp-19 is located in proximity to the C-terminal lobe of calmodulin in the complex.
mesh_terms: D020106:Acrylamide; D000178:Acrylamides; D001514:Bee Venoms / Q000378:metabolism*; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D002147:Calmodulin / Q000378:metabolism*; D002942:Circular Dichroism; D004735:Energy Transfer; D008433:Mathematics; D008555:Melitten / Q000378:metabolism*; D008956:Models, Chemical; D010446:Peptide Fragments / Q000378:metabolism; D011485:Protein Binding; D013050:Spectrometry, Fluorescence; D014268:Trifluoperazine / Q000378:metabolism; D014357:Trypsin
chemical_list: D000178:Acrylamides; D001514:Bee Venoms; D002147:Calmodulin; D010446:Peptide Fragments; D008555:Melitten; D020106:Acrylamide; D014268:Trifluoperazine; D014357:Trypsin; D002118:Calcium