PRESENT KNOWLEDGE CONCERNING AMINO-ACID SEQUENCE OF COW-KAPPA-CASEIN

IN a recent article, Hill and Wake1 suggested that the basis for the micelle stabilizing property of cow -casein was its amphiphile nature, for the N-terminal two-thirds of the molecule were hydrophobic and the C-terminal third hydrophilic. Their chemical structure data were chiefly based on some results of our group published some time ago2,3. We present here very briefly our present knowledge of the amino-acid sequences of cow -casein (Fig. 1). It is now clear that its peptide skeleton is almost homogeneous; a few changes attributable chiefly to genetic variants and variations in the sugar composition are ultimately responsible for the heterogeneity observed on electrophoresis2,4-6. The carbohydrate-free protein stabilizes αs-casein against precipitation by calcium1. It is thus sufficient for micelle stabilization, and it is attacked in the normal manner by rennin (EC 3.4.4.3)1,2,4. © 1969 Nature Publishing Group.