The size distribution and protein composition of casein micelles in the milk of Holstein-Friesian cows was determined as a function of stage and number of lactations. Protein composition did not vary significantly between the milks of different cows or as a function of lactation stage. Differences in the size and polydispersity of the casein micelles were observed between the milks of different...

In fresh milk, plasminogen, the zymogen form of plasmin (PL), is the predominant form. Therefore, plasminogen activators (PA) can contribute significantly to PL activity in milk. Both tissue-type PA (tPA) and urokinase-type PA (uPA) exist in milk; however, contradictory findings have been reported for which type of PA is most closely associated with the casein micelles. Little is known about th...

Caseins form heterogeneous micelles composed of three types of disordered protein chains (α, β, κ), which include protein-bound calcium phosphate particles. We probe the stability limits of the micelle by applying hydrostatic pressure. The resulting changes of the size distribution and the average molecular weight are recorded in situ with static and dynamic light scattering. Pressure induces i...

Milk is a heterogeneous fluid in which the colloidal phase is homogeneously dispersed in the aqueous phase. Calcium is partitioned between the colloidal and aqueous phases and is in complex electrochemical equilibrium with several major milk components. In human and bovine milk, calcium is mainly distributed between the aqueous and casein micelle in the colloidal phases (Holt & Jenness, 1984; N...

The nucleotide sequences corresponding to bovine crs2and p-casein mRNAs have been determined by cDNA analysis. Both sequences appear to be complete at their 5’ ends. The nucleotide sequence of us2-casein, when compared with the corresponding cavine A sequence, helps to define the boundaries of a large amino acid repeat (-80 residues) whereas comparisons with the nucleotide sequences of rat yand...