From the effects of N-acetyl-d-glucosamine and d-glucose on the elution of the A protein of human lactose synthetase from a column of Sepharose-alpha-lactalbumin, values of 200m(-1) and 0.57m(-1) are deduced for the association constants describing the interaction between the enzyme and the respective monosaccharides.

A double lumen jejunal perfusion technique has been used in man to study the effect of peptide chain length on absorption of amino acid nitrogen from two partial enzymic hydrolysates of lactalbumin. Copper-chelation chromatography showed that one lactalbumin hydrolysate (LH2) contained 98% peptides with a chain length greater than 4, whilst the other (LH1) contained a more even spread of chain ...

The effects of suckling intensity on milk yield and piglet growth were determined when lactation capacity of the sow was enhanced through overexpression of a mammary-specific transgene, bovine alpha-lactalbumin. Lactational response to increased suckling stimulation was determined by fostering litters of the same age (d 1) or 7 d older (d 7) than the day of lactation to sows nontransgenic (cont...

The ontogeny of the immune system and the effect thereon by type of infant feeding is incompletely understood. We analyzed frequencies and composition of immune cells in blood of breastfed (BF) and formula-fed (FF) infants at 1.5, 4, and 6 mo of age. Three formulas with the same protein concentration but with varying levels of alpha-lactalbumin and caseinoglycomacropeptide were compared. Twenty...

1. The effects of hypophysectomy and replacement therapy with sheep prolactin and bovine growth hormone on the lactose synthetase activity of the mammary glands of lactating rabbits were studied. 2. There was an approximately fourfold decline in the lactose synthetase activity of homogenates calculated on a DNA basis within 6-7 days of hypophysectomy. Prolactin reversed this decline but growth ...

Macromolecular absorption of gliadin, a wheat protein and alpha lactalbumin, a milk protein was evaluated in control and Escherichia coli enterotoxin (heat-stable, heat-labile, and both heat-stable and heat-labile enterotoxin) treated mice. The peak concentration of gliadin and lactalbumin was two hours and three hours after their ingestion, respectively. There was also a significant increase (...

Studies in the accompanying paper (Chen, W. W., and Lennarz, W. J. (1978) J. Biol. Chem. 253, 5774-5779) showed that hen oviduct membranes catalyze synthesis of a Glc-containing oligosaccharide-lipid and that the oligosaccharide moiety of this compound is transferred en bloc to an endogenous protein as well as to an exogenous, soluble protein. In this study we have established that the endogene...

Understanding the mechanisms of protein folding requires knowledge of both the energy landscape and the structural dynamics of a protein. We report a neutron-scattering study of the nanosecond and picosecond dynamics of native and the denatured alpha-lactalbumin. The quasielastic scattering intensity shows that there are alpha-helical structure and tertiary-like side-chain interactions fluctuat...

We present entropy estimates based on molecular dynamics simulations of models of the molten globule state of the protein alpha-lactalbumin at low pH. The entropy calculations use the covariance matrix of atom-positional fluctuations and yield the complete configurational entropy. The configurational entropy of the entire protein and of each of its side chains is calculated. Exposed side chains...

Foldons, which are kinetically competent, quasi-independently folding units of a protein, may be defined using energy landscape analysis. Foldons can be identified by maxima in a scan of the ratio of a contiguous segment's energetic stability gap to the energy variance of that segment's molten globule states, reflecting the requirement of minimal frustration. The predicted foldons are compared ...