User:Andy Maloney/Kinesin & Microtubule Page/Caseins of various origins and biologically active casein peptides and oligosaccharides Structural and physiological aspects

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These are my notes. Please read the paper before reading my notes.

Calcium sensitive components of casein are phosphorylated. Calcium insensitive components are glycosylated.
They give a definition for casein: The protein fraction precipitated from raw skim milk by acidification at pH 4.6 and 20˚C.
There are 4 major bovine casein groups: α_s1, α_s2, β, and κ.
α caseins are precipitated by small amounts of calcium.
beta-caseins are precipitated by moderate amounts of calcium.
kappa-caseins are calcium insensitive.
α_s1 has 5 variants: A, B, C, D, E.
- These have more acidic residues than basic ons.
- They have a high prolyl residue content ~8.5%.
- 3 hydrophobic residues.
- 2 hydrophilic regions.
- 8 - 9 phosphate groups linked to hydroxyamino acid residues.
beta-casein
- 7 variants: A¹, A², A³, B, C, D, E.
- 16.7% proline.
- Negative net charge.
kappa-casein
- 2 constituents: para-kappa-casein which is hydrophobic and kappa-caseinoglycopeptide which is hydrophilic.
  - The kappa-caseinoglycopeptide is where the sugars are.
- Negatively charged.
- No N-glycosidic linkages. They are all O-glycosidic linkages in the oligosacharides.
- Essential for casein micelle formation.
- 4 oligosacharides have Gal β in them. This is the core for murin type glycoproteins.
Phosphorylation is a post translational modification.
This paper related milk clotting to blood clotting.
It also describes lots of different milks from different species.
Talks about opioids.
Something else they talk about are fibrinogen.