Lactose Synthesis in a Monotreme, the Echidna (Tachyglossus aculeatus): Isolation and Amino Acid Sequence of Echidna α-Lactalbumin
Autor: | Peggy D. Rismiller, Michael Messer, Denis C. Shaw, Mervyn Griffiths |
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Rok vydání: | 1997 |
Předmět: |
animal structures
Physiology Tachyglossidae Molecular Sequence Data Lactose Monotreme Biochemistry chemistry.chemical_compound biology.animal Animals Amino Acid Sequence Molecular Biology Peptide sequence Galactosyltransferase Lactalbumin Sequence Homology Amino Acid biology Galactosyltransferases Milk Proteins biology.organism_classification chemistry Echidna Cattle Muramidase Lysozyme Platypus |
Zdroj: | Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology. 118:403-410 |
ISSN: | 1096-4959 |
DOI: | 10.1016/s0305-0491(97)00162-4 |
Popis: | alpha-Lactalbumin and lysozyme were each isolated from echidna (Tachyglossus aculeatus) milk by gel permeation and ion exchange chromatography. The alpha-lactalbumin modified the action of echidna milk galactosyltransferase to promote the synthesis of lactose but had very little effect on bovine galactosyltransferase. Echidna alpha-lactalbumin is a glycosylated protein with an apparent molecular weight of 20,000 (SDS-PAGE) whose concentration in the milk is very low compared with the concentrations of alpha-lactalbumin in the milk of other species. Its amino acid sequence is more similar to that of another monotreme, the platypus (Ornithorhynchus anatinus), than to the sequences of eutherian or marsupial alpha-lactalbumins. Echidna milk lysozyme, even at high concentrations, did not promote the synthesis of lactose by either echidna or bovine galactosyltransferase. We conclude that lactose synthesis in the echidna occurs by the same mechanism as that found in the platypus and other mammals. |
Databáze: | OpenAIRE |
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