Collagen

• Definition: Collagen is a protein supplement derived from animal sources like bones and connective tissue. It's rich in amino acids such as glycine, proline, and hydroxyproline.
• Purpose: Supports connective tissue health (skin, hair, nails, bones, joints) by providing building blocks for collagen production.
• Goal of Supplementation: To promote tissue strength, elasticity, and hydration, potentially improving skin texture, reducing joint pain, and enhancing well-being.

• Improved skin elasticity and hydration: Collagen supplementation increases skin elasticity, hydration, and density, reducing wrinkles and fine lines (1, 2).
• Joint health and pain relief: Reduces joint pain and inflammation, improves joint function, and promotes cartilage health (3, 4).
• Muscle mass and strength: Linked to increased muscle mass, strength, and muscle protein synthesis (5, 6).
• Bone health: Improves bone density, reducing osteoporosis and fracture risk (7, 8).
• Weight management: Aids in weight loss and maintenance, possibly due to satiety and improved glucose metabolism (9, 10).
• Improved glucose metabolism: Improves insulin sensitivity and glucose metabolism, reducing type 2 diabetes risk (11, 12).
• Neuroprotective effects: Exhibits neuroprotective properties, potentially reducing neurodegenerative disease risk (Alzheimer's, Parkinson's) (13, 14).
• Improved mood and anxiety: Linked to improved mood, reduced anxiety, and enhanced cognitive function (15, 16).
• Improved gut health: Promotes gut health, reducing inflammation and improving gut lining integrity (17, 18).
• Reduced IBS symptoms: Linked to reduced IBS symptoms (bloating, abdominal pain, diarrhea) (19, 20).
• Note: Supplement quality and efficacy vary depending on source, type, and manufacturing. Consult a healthcare professional before use.

• Abundance: Collagen is the most abundant protein in the human body (25-35% of all proteins).
• Connective Tissue Component: Key component of connective tissue, providing structural support, elasticity, and strength to organs, skin, bones, tendons, and ligaments.
• Biosynthesis and Structure: Synthesized through a multi-step process involving enzymes, vitamins, and minerals. Begins with collagen gene transcription, followed by translation into procollagen. Procollagen undergoes post-translational modifications (hydroxylation, glycosylation, proteolytic processing) to form mature collagen. Collagen comprises three alpha-helix chains forming a triple-helix structure. There are 28 types of collagen.
• Mechanism of Action:
  • Cell-matrix interactions: Provides a scaffold for cell attachment, migration, and differentiation; interacts with integrins to regulate cell behavior and tissue organization.
  • Mechanical properties: Triple-helix structure and cross-linking provide mechanical strength, elasticity, and stiffness.
  • Signaling pathways: Interacts with growth factors, cytokines, and signaling molecules to regulate cellular processes (proliferation, differentiation, survival).
  • Enzyme regulation: Binds and regulates enzymes, including matrix metalloproteinases (MMPs), involved in tissue remodeling and degradation.
• Pathways Affected:
  • Transforming growth factor-beta (TGF-β) pathway
  • Wnt/β-catenin pathway
  • PI3K/Akt pathway

• Abundance: Approximately 25-35% of all body proteins.
• Molecular Formula (Type I Collagen): (C₉₆H₁₄₇N₃₁O₃₄)₈₆₇ (approx. 285,000 g/mol)
• IUPAC Name: No specific IUPAC name; the repeating triplet is (2S)-2-amino-4-(4-hydroxyprolyl)-5-oxoproline.
• Key Structural Features:
  • Triple Helix Structure: Three polypeptide chains (alpha helices) twisted together.
  • Repeating Triplet Sequence: Glycine, proline, and hydroxyproline (repeated ~1000 times).
  • Glycine Residues: Smallest amino acid; allows tight packing of alpha helices.
  • Hydroxyproline and Hydroxylysine Residues: Unique to collagen; stabilize the triple helix.
  • Intra- and Intermolecular Cross-Links: Stabilize collagen molecules via lysine and hydroxylysine reactions.

• Natural Sources:
  • Bovine (cow) hide and bones (Type I and III)
  • Porcine (pig) skin and bones (Type I and III)
  • Marine sources (fish, shellfish) (Type I)
  • Chicken sternum and feet (Type II)
  • Eggshell membrane (Type I and V)
• Extraction/Synthesis Methods:
  • Hydrolysis (breaks down protein into smaller peptides and amino acids)
  • Enzymatic hydrolysis
  • Acid hydrolysis
  • Fermentation
  • Recombinant DNA technology
• Quality Considerations for Supplements:
  • Source and purity (free from contaminants and heavy metals)
  • Molecular weight (lower molecular weight <10,000 Da is more easily absorbed)
  • Bioavailability (ensure absorption and utilization)

(Note: References 1-20 are missing from the original text and need to be added for completeness.)