SECRETION OF ALPHA-LACTALBUMIN INTO MILK AND ITS RELEVANCE TO ORGANIZATION AND CONTROL OF LACTOSE SYNTHETASE

α-LACTALBUMIN has recently been recognized as a component of lactose synthetase1; it has long been known as a major protein component of milk whey2. Studies of the biosynthesis and secretion of α-lactalbumin in preparations from the lactating guinea-pig mammary gland3 indicate that the protein found in milk arises not by leakage and breakdown of mammary cells but is specifically secreted. The relatively high concentration of α-lactalbumin in milks, l mg/ml. in bovine milk4 and more than 5 mg/ml. in guinea-pig milk5, supports this view. © 1969 Nature Publishing Group.