Table 4.2 Properties of some milk proteins (modified from Walstra and Jenness, 1984)
Property
Caseins Whey proteins
Serum
u,,-B 8P GL.~-A 11P p-A’ 5P K-B 1P u-la-B P-10-B albumin
Molecular weight 23 614 25 230 23 983 19 023” 14 176 18 363 66 267
Residues/molecule
Amino acids 199 207 209 169 123 162 582
Proline 17 10 35 20 2 8 34
Cysteine 0 2 0 2 8 5 35
Intramolecular disulphide 0 0 0 0 4 2 17
0 0
0
Phosphate 8 11 5 1 0
Carbohydrate 0 0 0
Hydrophobicity (kJ/residue) 4.9 4.7 5.6 5.1 4.7 5.1 4.3
mol YO residues (^34 36 23 21 28 30 34)
Net charge/residue -0.10 - 0.07 -0.06 -0.02’ - 0.02 - 0.04 - 0.02
Distribution Uneven Uneven Very uneven Very uneven Even Even
bonds
b e d
Charge
A,,, 10.1 14.0’ 4.5 10.5 20.9 9.5 6.6
“Exclusive of carbohydrate residues.
bVariable, see text.
‘A small fraction of the molecules.
eAverage.
except for a rare variant (Dr).
’A29l.l.