In this study a-lactalbumin was converted from the regular, native state to a folding variant with altered biological function. The folding variant was shown to induce apoptosis in tumor cells and immature cells, but healthy cells were resistant to this effect. Conversion to HAMLET (human a-lactalbumin made lethal to tumor cells) required partial unfolding of the protein and a specific fatty ac...

Proteins of the same kind in human milk and cow's milk have different properties. Mellander (1947) reports differences in phosphorus content and the amount of carbohydrates of casein and that the casein of cow's milk is more easily digested by proteolytic enzymes in vitro than that of human milk. Kiyosawa, Ryoki & Maeno (1961) observed a marked difference in the solubility of casein and the tur...

The flux decline behaviour of some charged proteins and of binary mixtures of charged solutes during unstirred dead-end ultrafiltration has been studied. The mixtures consisted of the proteins bovine serum albumin, (BSA), cy-lactalbumin and/or lysozyme. Of special interest were a-lactalbumin and lysozyme because these proteins are physico-chemically identical, except for the sign of their charg...

Clusterin is an extracellular mammalian chaperone protein which inhibits stress-induced precipitation of many different proteins. The conformational state(s) of proteins that interact with clusterin and the stage(s) along the folding and off-folding (precipitation-bound) pathways where this interaction occurs were previously unknown. We investigated this by examining the interactions of cluster...

To determine whether lactalbumin production by normal and neoplastic human mammary tissue is under the same control, the effect of prolactin treatment was studied in organ culture. Of 9 premenopausal normal breast samples, 6 produced lac talbumin in culture, and all 6 responded to prolactin treatment over 4 days. One biopsy of pregnant breast tested also re sponded to prolactin treatment, produ...

Literature values for the Kd for Ca2 + in bovine a-lactalbumin range over 3 orders of magnitude. There is a difference between two results obtained with EGTA as a metalion buffer, partly because different values for the Kd of Ca2 +-EGTA were used in the calculations, and a much wider difference between results obtained in the presence and absence of EGTA, which has been attributed to an interac...

The molten globule, a widespread protein-folding intermediate, can attain a native-like backbone topology, even in the apparent absence of rigid side-chain packing. Nonetheless, mutagenesis studies suggest that molten globules are stabilized by some degree of side-chain packing among specific hydrophobic residues. Here we investigate the importance of hydrophobic side-chain diversity in determi...

To obtain insight into the functions of proteins and their specific roles, it is important to establish efficient procedures for exploring the states that encapsulate their conformational space. Global Protein folding State mapping by multivariate NMR (GPS NMR) is a powerful high-throughput method that provides such an overview. GPS NMR exploits the unique ability of NMR to simultaneously recor...

Mammary tissue from virgin, nulliparous, and multiparous primates of various species has been shown to contain a-lactalbumin, a milk protein. Production of alactalbumin by these tissues in organ culture was main tained or increased under the influence of prolactin. These findings provide evidence that mammary tissues, even in animals that are not pregnant or lactating, are active and responsive...

The alpha-lactalbumins and c-type lysozymes have virtually identical structure but exhibit very different folding behavior. All alpha-lactalbumins form a well populated molten globule state, while most of the lysozymes do not. alpha-Lactalbumin consists of two subdomains, and the alpha-subdomain is considerably more structured in the molten globule state than the beta-subdomain. Constructs deri...