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Sandbox WWCAlpha-S1-Casein
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| - | '''Alpha-S1-Casein (αs1-CN)''' is a calcium phosphate (CaP) binding protein found in bovine milk along with other caseins, including αs2- and β-casein (calcium-sensitive), and κ-casein (calcium insensitive).<ref>J. Dairy Sci., 67, 1599-1631, 1984, and from Table 1, J. Dairy Sci., 68, 2195-2205, 1985</ref> Although αs1-CN is the predominant casein (and protein overall) in bovine milk, the ratios of caseins vary considerably by species.<ref>doi: 10.1093/molbev/msr020< | + | '''Alpha-S1-Casein (αs1-CN)''' is a calcium phosphate (CaP) binding protein found in bovine milk along with other caseins, including αs2- and β-casein (calcium-sensitive), and κ-casein (calcium insensitive).<ref>J. Dairy Sci., 67, 1599-1631, 1984, and from Table 1, J. Dairy Sci., 68, 2195-2205, 1985</ref> Although αs1-CN is the predominant casein (and protein overall) in bovine milk, the ratios of caseins vary considerably by species.<ref>doi: 10.1093/molbev/msr020</ref> |
| - | Calcium-sensitive caseins such as αs1-CN bind with CaP, but will precipitate at high concentrations of CaP. In milk, | + | Calcium-sensitive caseins such as αs1-CN bind with CaP, but will precipitate at high concentrations of CaP. In milk, huge complexes are formed by calcium-sensitive caseins, CaP, and calcium-insensitive caseins. Precipitation of the calcium-sensitive caseins is prevented by the calcium-insensitive caseins stabilizing the complex to form a micelle. These micelles function to deliver calcium, phosphate, and protein to mammalian neonates. Unlike the whey proteins (all non-casein protein found in milk), caseins in micelles are relatively heat stable, although denaturation of the whey protein β-lactoglobulin at high temperatures can result in interactions with κ-casein that alters the structure of the casein micelles.<ref>Masoodi, T. A., & Shafi, G. (2010). Analysis of casein alpha S1 & S2 proteins from different mammalian species. Bioinformation, 4(9), 430–435.</ref> |
== Function == | == Function == | ||
Revision as of 22:05, 9 April 2015
Alpha-S1-Casein (αs1-CN) is a calcium phosphate (CaP) binding protein found in bovine milk along with other caseins, including αs2- and β-casein (calcium-sensitive), and κ-casein (calcium insensitive).[1] Although αs1-CN is the predominant casein (and protein overall) in bovine milk, the ratios of caseins vary considerably by species.[2]
Calcium-sensitive caseins such as αs1-CN bind with CaP, but will precipitate at high concentrations of CaP. In milk, huge complexes are formed by calcium-sensitive caseins, CaP, and calcium-insensitive caseins. Precipitation of the calcium-sensitive caseins is prevented by the calcium-insensitive caseins stabilizing the complex to form a micelle. These micelles function to deliver calcium, phosphate, and protein to mammalian neonates. Unlike the whey proteins (all non-casein protein found in milk), caseins in micelles are relatively heat stable, although denaturation of the whey protein β-lactoglobulin at high temperatures can result in interactions with κ-casein that alters the structure of the casein micelles.[3]
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Function
Disease
Relevance
Structural highlights
References
- ↑ J. Dairy Sci., 67, 1599-1631, 1984, and from Table 1, J. Dairy Sci., 68, 2195-2205, 1985
- ↑ Kawasaki K, Lafont AG, Sire JY. The evolution of milk casein genes from tooth genes before the origin of mammals. Mol Biol Evol. 2011 Jul;28(7):2053-61. doi: 10.1093/molbev/msr020. Epub 2011 Jan , 18. PMID:21245413 doi:http://dx.doi.org/10.1093/molbev/msr020
- ↑ Masoodi, T. A., & Shafi, G. (2010). Analysis of casein alpha S1 & S2 proteins from different mammalian species. Bioinformation, 4(9), 430–435.
