Casomorphin

Bovine β-casomorphin 7, a casomorphin, has seven amino acids in its peptide sequence.

Casomorphins are peptides, i.e., protein fragments, derived from the digestion of milk protein casein.^[1]

Health

Digestive enzymes can break casein down into peptides that have some biological activity in cells and in laboratory animals though conclusive causal effects on humans have not been established.^[1] Although they have not yet been proven to be formed in the human digestive system,^[2] there are associations between serum levels of β -casomorphins and the risk of sudden infant death syndrome,^[3] histamine release,^[4] stimulation of food intake, specifically high-fat foods,^[5] and lymphocytosis.^[6]

Although research has shown high rates of use of complementary and alternative therapies for children with autism, including gluten and/or casein exclusion diets, as of 2008 there was a lack of evidence that these diets had any effect.^[7]

Some known casomorphins

β-Casomorphin 1-3

• Structure: H-Tyr-Pro-Phe-OH
• Chemical formula: C₂₃H₂₇N₃O₅
• Molecular weight: 425.48 g/mo

Bovine β-casomorphin 1-4

• Structure: H-Tyr-Pro-Phe-Pro-OH
• Chemical formula: C28H35N4O6
• Molecular weight: 522.61 g/mol

Bovine β-casomorphin 1-4, amide

• Structure: H-Tyr-Pro-Phe-Pro-NH₂
• Chemical formula: C₂₈H₃₅N₅O₅
• Molecular weight: 521.6 g/mol

Also known as morphiceptin

Bovine β-casomorphin 5

• Structure: H-Tyr-Pro-Phe-Pro-Gly-OH
• Chemical formula: C₃₀H₃₇N₅O₇
• Molecular weight: 594.66 g/mol

Bovine β-casomorphin 7

• Structure: H-Tyr-Pro-Phe-Pro-Gly-Pro-Ile-OH
• Chemical formula: C₄₁H₅₅N₇O₉
• Molecular weight: 789.9 g/mol

Bovine β-casomorphin 8

• Structure: H-Tyr-Pro-Phe-Pro-Gly-Pro-Ile-Pro-OH
• Chemical formula: C₄₆H₆₂N₈O₁₀
• Molecular weight: 887.00 g/mol

(Note: There is also a form of bovine β-Casomorphin 8 that has histidine instead of proline in position 8, depending on whether it is derived from A1 or A2 beta-casein.)

References

1. European Food Safety Authority. 1 February 2009 Review of the potential health impact of β -casomorphins and related peptides
2. Clemens, RA (2011). "Milk A1 and A2 peptides and diabetes" (PDF). Nestle Nutr Workshop Ser Pediatr Program 67: 187–95. doi:10.1159/000325584. PMID 21335999.
3. Wasilewska, J; Sienkiewicz-Szłapka, E; Kuźbida, E; Jarmołowska, B; Kaczmarski, M; Kostyra, E (2011). "The exogenous opioid peptides and DPPIV serum activity in infants with apnoea expressed as apparent life threatening events (ALTE).". Neuropeptides 45 (3): 189–95. doi:10.1016/j.npep.2011.01.005.
4. Kurek, M; Przybilla, B; Hermann, K; Ring, J (1992). "A naturally occurring opioid peptide from cow’s milk, beta-casomorphine-7, is a direct histamine releaser in man.". Int Arch Allergy Immunol 97 (2): 115–20. doi:10.1159/000236106.
5. Lin, L; Umahara, M; York, DA; Bray, GA (1998). "Beta-casomorphins stimulate and enterostatin inhibits the intake of dietary fat in rats.". Peptides 19 (2): 325–331. doi:10.1016/S0196-9781(97)00307-0.
6. Kayser, H; Meisel, H (1996). "Stimulation of human peripheral blood lymphocytes by bioactive peptides derived from bovine milk proteins.". FEBS Lett 383 (1-2): 18–20. doi:10.1016/0014-5793(96)00207-4.
7. Millward, C; Ferriter, M; Calver, S; Connell-Jones, G (2008). "Gluten- and casein-free diets for autistic spectrum disorder". Cochrane Database of Systematic Reviews: CD003498. doi:10.1002/14651858.CD003498.pub3. PMC: 4164915. PMID 18425890.