Human Collagen IV  alpha 1 Alexa Fluor™ Plus 488‑conjugated Antibody

COL4A1 (collagen IV alpha 1) is a 185 kDa member of the type IV collagen family.  It is a secreted glycoprotein that is expressed by multiple cell types, including fibroblasts, keratinocytes and endothelial cells.  Two COL4A1 molecules interact with a 170 kDa alpha 2 chain to form a collagen IV triple helix.  This helix further interacts with other helices to generate covalent oligomers that form a scaffold in the basement membrane.  Mature human COL4A1 is 1642 amino acids (aa) in length.  It has an N-terminal “7S” proregion (aa 28-172), a central collagenous domain that contains multiple Gly-based repeats (aa 173-1440), and a C-terminal domain that is proteolytically cleaved to generate a 25-28 kDa NC1 globular segment that has potent antiangiogenic activity (aa 1441-1669).  Multiple splice forms exist.  One shows a deletion of aa 499-849, a second shows a seven aa substitution for aa 513-1669, and a third shows a seven aa substitution for aa 958-1669.  Over aa 1441-1669, human COL4A1 is 97% aa identical to mouse COL4A1.