TY - JOUR
T1 - The effect of C-terminal deletion on the folding and self-association of recombinant non-phosphorylated human β-casein
AU - Bu, Hongyin
AU - Sood, Satish M.
AU - Slattery, Charles W.
N1 - Recombinant human ß-casein (CN) mutants were prepared having 11, 22 and 31 amino acids (aa) deleted from the C-terminus. The temperature-dependent self-association of these and the wild-type recombinant was studied by turbidity (OD400) while possible folding differences were examined by intrinsic and extrinsic fluorescence intensity and fluorescence resonance energy transfer.
PY - 2004/11
Y1 - 2004/11
N2 - Recombinant human β-casein (CN) mutants were prepared having 11, 22 and 31 amino acids (aa) deleted from the C-terminus. The temperature-dependent self-association of these and the wild-type recombinant was studied by turbidity (OD_{400}) while possible folding differences were examined by intrinsic and extrinsic fluorescence intensity and fluorescence resonance energy transfer. There were major self-association and some conformational differences. Hydrophobicity profile and hydrophobic cluster analysis for bovine and human β-CN suggested that the ability of the 31 aa deletion mutant in human β-CN to self-associate when a comparable bovine deletion peptide would not may be due to the presence of additional hydrophobic regions in the middle, indicating that the human protein may contain more than a single hydrophobic binding locus and suggesting that the process for the formation and structure of the micelles of human milk may be quite different from that for bovine milk. A new model may be needed.
AB - Recombinant human β-casein (CN) mutants were prepared having 11, 22 and 31 amino acids (aa) deleted from the C-terminus. The temperature-dependent self-association of these and the wild-type recombinant was studied by turbidity (OD_{400}) while possible folding differences were examined by intrinsic and extrinsic fluorescence intensity and fluorescence resonance energy transfer. There were major self-association and some conformational differences. Hydrophobicity profile and hydrophobic cluster analysis for bovine and human β-CN suggested that the ability of the 31 aa deletion mutant in human β-CN to self-associate when a comparable bovine deletion peptide would not may be due to the presence of additional hydrophobic regions in the middle, indicating that the human protein may contain more than a single hydrophobic binding locus and suggesting that the process for the formation and structure of the micelles of human milk may be quite different from that for bovine milk. A new model may be needed.
KW - Fluorescence resonance energy transfer
KW - Human β-casein
KW - Hydrophobic binding loci
KW - Intrinsic and extrinsic fluorescence intensity
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U2 - 10.1007/s10930-004-7878-y
DO - 10.1007/s10930-004-7878-y
M3 - Article
C2 - 15648973
SN - 1572-3887
VL - 23
SP - 509
EP - 517
JO - Protein Journal
JF - Protein Journal
IS - 8
ER -