Collagenase inhibition by cationic proteins derived from cartilage and aorta.

Modulator protein, a brain troponin C-like protein, has been coupled to Sepharose 4B using conditions that allow retention of phosphodiesterase stimulatory activity. This conjugate has been used to directly demonstrate the calcium dependent formation of a reversible modulator protein-phosphodiesterase complex and to purify a cyclic nucleotide phosphodiesterase by affinity chromatography.