Chemical cleavage of bovine beta-lactoglobulin B by hydroxylamine

The objectives of this study were to assess whether chemical cleavage of be ta-lactoglobulin (beta-Lg) by hydroxylamine would result in a high yield of homogeneous, easily purifiable fragments, which could subsequently be used in structure-functionality studies. Cleavage was performed at 2 temperatur es and in the presence and absence of guanidine-HCl, and selected hydrolysi s products were isolated and characterized. beta-Lg was primarily cleaved a t Asn-Gly,as expected, into 2 fragments of 7 and 11 kDa, respectively. Addi tional cleavage at other Asn-X bonds also occurred. The 2 major fragments b ath contained some heterogeneity due to modification by hydroxylation and/o r cleavage at other Asn-X bonds.