Recombinant human Endoplasmic reticulum protein SC65 (P3H4) fragment (residues 19-378) is a high-quality protein product designed for structural and biochemical studies. This 360-amino acid fragment represents a stable and soluble unit, ideal for investigating collagen hydroxylation and fibril assembly mechanisms.

The full-length Endoplasmic reticulum protein SC65 (P3H4) is a critical component of a complex with PLOD1 and P3H3 that catalyzes lysine hydroxylation in collagen alpha chains. This enzymatic activity is essential for proper collagen fibril assembly, cross-linking, and overall extracellular matrix integrity. The protein's function directly contributes to normal bone density and skin stability. As an endoplasmic reticulum-resident protein, it operates within the cellular compartment responsible for protein folding and post-translational modifications, positioning it centrally in collagen biosynthesis pathways.