Type IV Collagen, Catalog Number 5022, NC1 and 7s Domains
Type IV Collagen, Catalog Number 5022, has not specifically been tested for NC1 or 7s domains. Alpha chains of type IV collagen have a non-collagenous domain (NC1) at their C-terminus, frequent interruptions of the G-X-Y repeats in the long central triple-helical domain (which may cause flexibility in the triple helix and pepsin sensitivity), and a short N-terminaltriple-helical 7s domain made of 25 amino-acids residues. Four molecules of type IV collagen are linked via the amino-terminal region. This disulfide rich cross-linking domain, called 7s collagen, is itself resistant to various proteases, including bacterial collagenase. For these two reasons, we believe the 7s domain of placental collagen may have partly resisted the mild pepsin digestion we applied on the placental tissue.
However pepsinized type IV collagen depleted of the 7s domain may be prepared, as described by Timpl et al. (1983). Timpl, R., S. Johansson, V. van Delden, I. Oberbaumer, and M. Hook. 1983.Characterization of protease resistant fragments of laminin mediating attachment and spreading of rat hepatocytes. J. Biol. Chem. 258:8922-8927.
