Genetic variants of bovine beta-lactoglobulin. A novel wild-type beta-lactoglobulin W and its primary sequence.
A novel bovine beta-lactoglobulin W has been isolated and its complete primary structure is presented. It was isolated by chromatofocusing of a beta-lactoglobulin AW heterozygote and purified by recrystallization. During sequencing of the oxidized protein, it became evident that the new beta-lactoglobulin W is a subtype of variant B with a single difference at position 56. This Ile----Leu substitution, which means a shift of a methyl group from C-beta to C-gamma of the amino-acid side chain causes a change of pI of 0.007 units, which can be detected by high resolution electrophoresis. This Ile56 amino-acid residue is among the most conserved residues with the exception of kangaroo beta-LG. The structures of other bovine beta-lactoglobulins and their relationships are discussed.
Godovac-Zimmermann
J
J
John Curtin School of Medical Research, Australian National University, Canberra.
Krause
I
I
Buchberger
J
J
Weiss
G
G
Klostermeyer
H
H
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D005260:Female; D006579:Heterozygote; D007782:Lactoglobulins / Q000032:analysis* / Q000235:genetics*; D008969:Molecular Sequence Data; D013045:Species Specificity
D007782:Lactoglobulins; C064259:beta-lactoglobin W