Chondrocalcin and the calcification of cartilage. A review.

A protein recently identified and named chondrocalcin is associated with the calcification of hyaline cartilage matrix in health and disease. Chondrocalcin is absent from noncalcifying growth plate cartilages in disease. It is also present in noncalcifying developing epiphyseal cartilage. The molecule appears to be synthesized and secreted by chondrocytes, particularly those committed to becoming hypertrophic. It is not detectable in developing or mature bone, teeth, or other tissues, although trace amounts are present in blood. The assigned molecular weight is 69,000. The protein is basic and is constructed of two subunits of 35,500 and 34,500.