Comparison of the Cu2+ binding to bovine, goat and human alpha-lactalbumin.
Cu2+ binds to bovine alpha-lactalbumin at two different sites, principally at a hystidyl residue and in second instance at a deprotonated amide group. In human alpha-lactalbumin, that is lacking His 68, only the second binding site was observed, so that evidence is given that His 68 in bovine alpha-lactalbumin is responsible for the major Cu2+ binding. In goat alpha-lactalbumin, the histidyl binding effectively occurs but only to a lesser degree as the accessibility of His 68 is reduced by the greater compactness of goat alpha-lactalbumin. In the three species the Cu2+ binding is independent on the occupation of the primary Ca(2+)- site.
Tieghem
E
E
Interdisciplinair Research Centrum, K.U. Leuven Campus Kortrijk, Belgium.
Van Dael
H
H
Van Cauwelaert
F
F
D000588:Amines / Q000378:metabolism; D000818:Animals; D001059:Apoproteins / Q000378:metabolism; D001665:Binding Sites; D002417:Cattle; D002942:Circular Dichroism; D003300:Copper / Q000378:metabolism*; D006041:Goats; D006639:Histidine / Q000378:metabolism; D006801:Humans; D007768:Lactalbumin / Q000378:metabolism*; D008892:Milk; D011485:Protein Binding; D011487:Protein Conformation; D011522:Protons; D013053:Spectrophotometry
D000588:Amines; D001059:Apoproteins; D011522:Protons; D006639:Histidine; D003300:Copper; D007768:Lactalbumin