- The synaptic vesicle protein synaptotagmin associates with calcium channels and is a putative Lambert-Eaton myasthenic syndrome antigen. Leveque, C., Hoshino, T., David, P., Shoji-Kasai, Y., Leys, K., Omori, A., Lang, B., el Far, O., Sato, K., Martin-Moutot, N. Proc. Natl. Acad. Sci. U.S.A. (1992)