Biological Actions of Calcium

Abstract

This meeting is being held to celebrate a great advance that was made forty years ago by Professor Setsuro Ebashi. This was the discovery of the substance “troponin”,1 a component of the thin filaments of striated muscle of vertebrates. A few years earlier,2 Ebashi had given direct evidence that calcium ions, at a concentration of a few micromolar, cause contraction of actomyosin preparations. This was a remarkable achievement, since at that time calcium chelators were not available, and the level of calcium impurities had to be kept down by extreme care in preparation of his solutions. This observation was made while Ebashi was spending a year in the laboratory of Fritz Lipmann in New York. On his way back to Japan in 1960, he passed through Britain and took the opportunity of coming to Cambridge to visit Alan Hodgkin and myself. He told us of his observations, and also said that Lipmann had been unwilling to accept that anything as simple as a calcium ion could perform such an important and specific function, and that this had delayed Ebashi’s publication of his results. Later, Ebashi told me that he had been much encouraged by my enthusiastic response to what he told us.