Human Collagen Type III protein purified from human placenta. 

Type III collagen is a fibrillar collagen, and it consists of only one collagen α chain, in contrast to most other collagens. It is a homotrimer containing three α1(III) chains supercoiled around each other in a right-handed triple helix. Type III collagen is secreted by fibroblasts and other mesenchymal cell types, thus making it a major player in various inflammation-associated pathologies such as lung injury, viral and nonviral liver diseases, kidney fibrosis, hernia, and vascular disorders. Type III collagen together with type I collagen are the main constituents of the interstitial matrix.