Cartilage oligomeric matrix protein is a calcium-binding protein, and a mutation in its type 3 repeats causes conformational changes.
Chen, H, M Deere, J T Hecht, and J Lawler. 2000. “Cartilage Oligomeric Matrix Protein Is a Calcium-Binding Protein, and a Mutation in Its Type 3 Repeats Causes Conformational Changes.”. The Journal of Biological Chemistry 275 (34): 26538-44.