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

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Disclaimer

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

Paper

Caseins of various origins and biologically active casein peptides and oligosaccharides: Structural and physiological aspects

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: αs1, αs2, 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.
  • αs1 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.