A new preparation of S-100 protein from rat and bovine brains.

The S-100 nervous system protein was purified from bovine and rat brains by a modification of the original procedure. The main modification consisted in substituting a step of calcium-dependent binding of S-100 to a phenyl-Sepharose column for the original step of chromatography on G-200 Sephadex. The proteins were pure as determined by SDS gel electrophoresis. HPLC on a reversed phase and on a size-separation column, and by immunological criteria. The bovine S-100 behaved as previously described, during calcium binding, by displaying a conformational change as evidenced by increase in native fluorescence.