TY - JOUR
T1 - The formation of casein micelles reconstituted with Ca+2 and added inorganic phosphate is influenced by the non-phosphorylated form of human β-casein
AU - Sood, Satish M.
AU - Erickson, Grant
AU - Slattery, Charles W.
N1 - The beta-casein (CN) human milk fraction is comprised of a single protein phosphorylated at levels from 0 to 5. Component interactions are dependent on the phosphorylation level. Here, 3 mg/ml of beta-CN-0P, beta-CN-2P, beta-CN-4P, a 2P/4P 1:1 (wt:wt) mixture, or a mixture of all six forms in the ratio in human milk, were mixed with bovine kappa-CN at a kappa/beta molar ratio of 0.33.
PY - 2005/5
Y1 - 2005/5
N2 - The β-casein (CN) human milk fraction is comprised of a single protein phosphorylated at levels from 0 to 5. Component interactions are dependent on the phosphorylation level. Here, 3 mg/ml of β-CN-0P, β-CN-2P, β-CN-4P, a 2P/4P 1:1 (wt:wt) mixture, or a mixture of all six forms in the ratio in human milk, were mixed with bovine κ-CN at a κ/β molar ratio of 0.33. Measurements were with 0, 5 and 10 mM Ca+2 and 4 and 8 mM added inorganic phosphate (Pi). The turbidity (OD 400 nm) and a lack of precipitation as T increased from 4 to 37°C was an index of micelle formation. The results indicate: (1) while micelles will form with Ca+2 alone, added Pi has a significant enhancing effect on micelle formation; (2) the patterns of micelle formation as a function of T are influenced by the β-CN-0P and β-CN-1P forms of β-CN to an unexpected extent.
AB - The β-casein (CN) human milk fraction is comprised of a single protein phosphorylated at levels from 0 to 5. Component interactions are dependent on the phosphorylation level. Here, 3 mg/ml of β-CN-0P, β-CN-2P, β-CN-4P, a 2P/4P 1:1 (wt:wt) mixture, or a mixture of all six forms in the ratio in human milk, were mixed with bovine κ-CN at a κ/β molar ratio of 0.33. Measurements were with 0, 5 and 10 mM Ca+2 and 4 and 8 mM added inorganic phosphate (Pi). The turbidity (OD 400 nm) and a lack of precipitation as T increased from 4 to 37°C was an index of micelle formation. The results indicate: (1) while micelles will form with Ca+2 alone, added Pi has a significant enhancing effect on micelle formation; (2) the patterns of micelle formation as a function of T are influenced by the β-CN-0P and β-CN-1P forms of β-CN to an unexpected extent.
KW - Colloidal calcium phosphate
KW - Human β-casein
KW - Protein phosphorylation level
KW - Reconstituted milk micelle formation
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U2 - 10.1007/s10930-005-6715-2
DO - 10.1007/s10930-005-6715-2
M3 - Article
C2 - 16283545
SN - 1572-3887
VL - 24
SP - 227
EP - 232
JO - Protein Journal
JF - Protein Journal
IS - 4
ER -