Figure 3
From: Cardiac fibroblasts, fibrosis and extracellular matrix remodeling in heart disease
Structure of collagen molecule. Pro-collagen is comprised of two alpha-1 chains and one alpha-2 chain intertwined into a triple helix. Pro-peptide domains at the carboxy-terminals and amino-terminals are cleaved, resulting in formation of mature collagen. When collagen is degraded, during physiological turnover or pathological adverse remodeling, telopeptides (from the amino-terminals or carboxy-terminals) are cleaved and released into the plasma.