Beta Isomer of C-Terminal Telopeptide of Type I Collagen

**Semantic type:** Amino Acid, Peptide, or Protein

**Definition:** This polypeptide is comprised of the proteolytically released carboxy-terminal portions of fibrillar type I collagen where age has converted the alpha form of aspartic acid to its beta form. These peptides are joined through trivalent crosslinks and are products of the degradation of mature type I collagen. Elevated serum concentrations of beta-CTX are associated with increased bone resorption.

**Synonyms:** - Beta Isoform of the Carboxy-Terminal Cross-Linking Telopeptide of Type I Collagen - Beta Isoform of the Cross-Linked C-Terminal Telopeptide of Type I Collagen - Beta-C-Telopeptide of Type I Collagen - Beta-CTX - Beta-CTx - Beta-CrossLaps - BetaCTx