Structural highlights
Function
[LALBA_HUMAN] Regulatory subunit of lactose synthase, changes the substrate specificity of galactosyltransferase in the mammary gland making glucose a good acceptor substrate for this enzyme. This enables LS to synthesize lactose, the major carbohydrate component of milk. In other tissues, galactosyltransferase transfers galactose onto the N-acetylglucosamine of the oligosaccharide chains in glycoproteins.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
It has been proposed that the binding of Zn2+ to alpha-lactalbumin switches the conformation to one akin to a state intermediate in the folding of the protein. However, the high resolution x-ray crystal structure of human alpha-lactalbumin-Zn2+ complex at 1.7-A resolution (pH 7.6) does not reveal any significant change in conformation from the native state. The Zn2+ ion binds specifically in the "cleft" of alpha-lactalbumin (the region which forms the active site of the homologous protein lysozyme). This may suggest a possible role for Zn2+ binding in lactose synthase complex. The coordination of the Zn2+ ion involves a symmetry-related molecule in the crystal, the crystal contacts being stabilized by a SO4(2-) ion bound at the interface between three molecules.
Alpha-lactalbumin possesses a distinct zinc binding site.,Ren J, Stuart DI, Acharya KR J Biol Chem. 1993 Sep 15;268(26):19292-8. PMID:8366079[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Ren J, Stuart DI, Acharya KR. Alpha-lactalbumin possesses a distinct zinc binding site. J Biol Chem. 1993 Sep 15;268(26):19292-8. PMID:8366079
