When milk is ingested, casein micelles will be successively digested by pepsin in the stomach and trypsin in the intestine. Therefore, we digested casein micelles successively with pepsin at pH 4.0 and trypsin at pH 7.0, and recovered casein phosphopeptides (CPP) as CPP-calcium phosphate (CP) complexes. The CPP-CP complexes contained 248 mg of calcium/g peptides and 175 mg of inorganic phosphor...

A casein-type protein kinase has been isolated from cauliflower (Brassica cauliflora Gars.) nuclei and purified to a specific activity of 23,000 units/milligram of protein (1 unit is defined as the transfer of 1 picomole of (32)Pi from gamma-[(32)P]ATP to substrate per minute at 28 C). The enzyme has a molecular weight of approximately 39,000 as judged by sucrose density gradient sedimentation....

The mPER1 and mPER2 proteins have important roles in the circadian clock mechanism, whereas mPER3 is expendable. Here we examine the posttranslational regulation of mPER3 in vivo in mouse liver and compare it to the other mPER proteins to define the salient features required for clock function. Like mPER1 and mPER2, mPER3 is phosphorylated, changes cellular location, and interacts with other cl...

1. Adult female rats given a diet containing 200 g casein/kg showed an increase in heat production which reached a maximum in 10--20 min after completion of food intake. 2. Replacement of casein in the diet by enzymic hydrolysates of casein of different extents of hydrolysis (pepsin for 1 or 3 h and pancreatin for 6, 12 or 24 h) resulted in a decrease in metabolic rate (stimulation) in the rat,...

Lactating goats fed a basal ration containing 11% crude protein, were infused intra-abomasally with 45g/d of either casein or glucose, in an attempt to determine whether milk production responsesto casein infusions could be attributed to gluconeogenesis from the casein. Infusions of casein increased the production of milk and milk constituents whereas the-production during glucose infusions was...

Little is known about how milk proteins affect gastrointestinal (GI) transit, particularly for the elderly, in whom digestion has been observed to be slowed. We tested the hypothesis that GI transit is faster for whey than for casein and that this effect is accentuated with hydrolysates, similar to soy. Adult male rats (18 months old) were fed native whey or casein, hydrolyzed whey (WPH) or cas...

Phosphorylation of rabbit muscle glycogen synthase by cyclic AMP-dependent protein kinase has been shown to enhance subsequent phosphorylation by casein kinase I (Flotow, H., and Roach, P. J. (1989) J. Biol. Chem. 264, 9126-9128). In the present study, synthetic peptides based on the sequences of the four phosphorylated regions in muscle glycogen synthase were used to probe the role of substrat...

The present study compared the effects of a high- and normal-casein-protein breakfast on satiety, 'satiety' hormones, plasma amino acid responses and subsequent energy intake. Twenty-five healthy subjects (BMI 23.9 (SEM 0.3) kg/m2; age 22 (SEM 1) years) received a subject-specific standardised breakfast (20% of daily energy requirements): a custard with casein as the single protein source with ...

Casein is a major protein in cow's milk that occurs in several variant forms, two of which are beta-casein A1 and beta-casein A2. The levels of these two proteins vary considerably in milk dependent on the breed of cow, and epidemiology studies suggest that there is a relationship between their consumption and the degree of atherosclerosis. In the present study, the direct effect of consumption...

We report the molecular cloning and characterization of a 49-kDa form of casein kinase I from rat testis. A cDNA clone encoding the enzyme, designated casein kinase I delta, contained an open reading frame of 1284 nucleotides that predicts a polypeptide of 428 amino acids with a M(r) of 49,121. The predicted amino acid sequence shares 76% identity with casein kinase I alpha, a 37-kDa form recen...