Purification and properties of two forms of rat alpha-lactalbumin.
Two species of alpha-lactalbumin, alpha-lactalbumin1 and alpha-lactalbumin2, were separated from rat milk and purified to homogeneity by gel filtration, followed by the DEAE-cellulose chromatography. alpha-Lactalbumin1 is a bigger molecule in contrast to other known alpha-lactalbumins, and has a molecular weight of 21,500 as determined by sedimentation equilibrium and sodium dodecyl sulfate-polyacrylamide gel analysis. alpha-Lactalbumin2 has a molecular weight of 16,000 measured by sedimentation analysis. alpha-Lactalbumin2, however, exhibits abnormally high molecular weight of 22,500 on sodium dodecyl sulfate polyacrylamide gels. Both alpha-lactalbumins are active in lactose synthase assay and are glycoproteins containing 7 to 9% carbohydrate. Antiserum raised against alpha-lactalbumin1 cannot discriminate between the two species in a radioimmunoassay.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D002417:Cattle; D005260:Female; D005700:Galactosyltransferases / Q000302:isolation & purification; D007768:Lactalbumin / Q000302:isolation & purification; D007788:Lactose Synthase / Q000378:metabolism; D008892:Milk / Q000032:analysis* / Q000201:enzymology; D008970:Molecular Weight; D011247:Pregnancy; D011863:Radioimmunoassay; D051381:Rats; D013379:Substrate Specificity
D000596:Amino Acids; D002241:Carbohydrates; D007768:Lactalbumin; D005700:Galactosyltransferases; D007788:Lactose Synthase