Structure of bovine β-lactoglobulin at 6Å resolution

Crystal structures of bovine β‐lactoglobulin in the orthorhombic space group C2221

“…BLG belongs to the lipocalin family, which includes mouse major urinary protein [3], retinol‐binding protein [4], α 2u ‐globulin [3–5] and insecticyanin [6] and, in keeping with the family, the overall structure of BLG has been extensively described as a calyx composed of an eight‐stranded antiparallel β sheet (Fig. 1) [7–11]. Although the biophysical and biochemical properties of the protein have been thoroughly investigated, its biological function remains unknown.…”

“…The first X‐ray diffraction study of BLG was reported in 1938 [31]. Different crystal forms of the protein are known [7–32]. Those that grow from salt at physiological pH have been named lattices X, Y and Z and belong to the space groups P1, C222 1 and P3 2 21, respectively.…”

“…Those that grow from salt at physiological pH have been named lattices X, Y and Z and belong to the space groups P1, C222 1 and P3 2 21, respectively. The structures of BLG were determined at low resolution in lattices X, Y and Z [7] and, later, at medium resolution in lattice Y [8] and in lattice Z [9]. These structures, however, had several ill‐defined regions and attempts to refine them were unsuccessful.…”

“…The trigonal crystal form has also been used to compare structures of BLG genetic variants A and B both crystallized at pH 7.1 [33]. Surprisingly, the only significant structural difference found between genetic variants was again the conformation of the EF loop (residues 85–90), previously implied in the Tanford transition [7]. This finding is at variance with physicochemical studies that demonstrate that the midpoint of the Tanford transition lies at pH 7.3 both for genetic variants A and B [34–36].…”

Formation of Fouling Deposit from Several Soft Drinks on Stainless Steel Surfaces.

“…In the case of model p-lactoglobulin solutions with and without tannic acid, the amount of protein deposited was calculated from the amount of nitrogen. Taking into consideration the amino acid composition of p-lactoglobulin (Green et a/., 1979), I g of nitrogen corresponds to 7.5 g of~-1actoglobulin.…”