Denatured type IV collagen cryptic epitope (HU177 epitope) (HU177 epitope)

The HU177 cryptic epitope is a specific molecular site on type IV collagen that is exposed only when the protein undergoes denaturation or proteolytic cleavage, typically by matrix metalloproteinases (MMPs) (Brooks et al., Cell, 1998). Type IV collagen is the primary structural scaffold of the vascular basement membrane, and in its native state, the HU177 epitope is hidden within the triple helix. During pathological angiogenesis associated with tumor growth and ocular diseases, the basement membrane is remodeled, exposing this epitope to the microenvironment. Therapeutic agents such as the monoclonal antibody HU177 and its humanized version TRC093 target this site to selectively inhibit neovascularization without affecting quiescent vessels (Xu et al., Hybridoma, 2001). Binding to the epitope disrupts the interaction between endothelial cells and the remodeled matrix, leading to endothelial cell apoptosis and suppression of tumor growth (Tracon Pharmaceuticals, 2024). This target is particularly significant because it allows for the selective targeting of 'angiogenic' collagen rather than the ubiquitous native collagen found in healthy tissues.

Other names

Cryptic collagen IV epitopeDenatured collagen IV epitopeHU177-binding siteRemodeled type IV collagen epitopeAngiogenic cryptic site within collagen type IV

Selective inhibition of angiogenesis by inducing apoptosis in activated endothelial cells and disrupting cell-matrix interactions required for neovascularization.