The monomeric β -lactoglobulin (β-lg) is a small globular protein a molecular weight of
18.4 kDa, member of the lipocalin family of proteins [1]. This protein consists of a single
polypeptide chain of 162 amino which are organized into 8-stranded antiparallel β-barrel with a
3-turn α-helix on the outer surface and a ninth β-strand flanking the first strand (Fig. 1).
Β-lg was identified in the milk of many mammalian species, excepting the human,
lagomorphs and rodent milks, where it was absent. It was established that β-lg is the main fraction
of the whey protein in bovine milk [2]. Although, this protein has been extensively studied, its
biological functions are still unknown.
In aqueous solutions, β-lg undergoes aggregation processes as a result of various conditions
[3]. The study of homo-association (Fig. 1) and formation of oligomeric states of β-lg will give
some insights into the functional properties of this protein. We have studied the influence of pH
and concentration on aggregation process and the morphology of β-lg aggregates. In all cases,
small angle neutron scattering was essential to determine the three-dimensional models of the
homo-associates of β-lg.

Fig. 1. Graphical representation of unliganded monomeric form of bovine β –lactoglobulin (PDB entry 5IO5)
and its homo-dimer.
[1] T. Phan-Xuan, et al., Food Hydrocolloids. 34 (2012), pp. 227–235.
[2] L. Sawyer, G. Kontopidis. Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular
Enzymology. 1482, 1-2(2000), pp. 136–148.
[3] P.R. Majhi, et al., Langmuir. 22, 22 (2006), pp. 9150-9159.