Identification of the Coated Vesicle Proteins That Bind Calmodulin
ARMY MEDICAL RESEARCH INST OF INFECTIOUS DISEASES FORT DETRICK MD VIROLOGY DIV
Pagination or Media Count:
The constituent proteins of coated vesicles responsible for binding calmodulin were identified by photoaffinity labeling with the reagent azido-125I-calmodulin. Three protein complexes with apparent molecular weights of 130,000, 93,000 and 52,000 were labeled. Specificity was demonstrated by the dependence of labeling on Ca2, and by its reduction in the presence of unlabeled calmodulin or Stelazine. Urea-soluble components of coated vesicles and material isolated by Sepharose CL4B chromatography formed a 52,000 MW labeled complex. Subtracting an apparent molecular weight of calmodulin of 20,000 from the weights of the covalently labeled complexes, the coated vesicle proteins that bind calmodulin are 110,000, 73,000, and 32,000 MW. The 32,000 MW protein is thought to participate in the coat structure but the other two are most likely associated with the vesicle.