Ulster University Logo

Ulster Institutional Repository

The effect of calcium on bovine α-lactalbumin conformational transitions by ultraviolet difference and fluorescence spectrophotometry

Biomedical Sciences Research Institute Computer Science Research Institute Environmental Sciences Research Institute Nanotechnology & Advanced Materials Research Institute

Owusu, RK (1992) The effect of calcium on bovine α-lactalbumin conformational transitions by ultraviolet difference and fluorescence spectrophotometry. Food Chemistry, 43 (1). pp. 41-45. [Journal article]

Full text not available from this repository.

URL: http://dx.doi.org/10.1016/0308-8146(92)90239-X

DOI: doi:10.1016/0308-8146(92)90239-X

Abstract

The unfolding of bovine α-lactalbumin (BAL) in guanidine hydrochloride (GnHCl) was studied by UV difference and fluorescence spectrophotometry. When BAL was dissolved in calcium-free solvents, nonsuperimposable unfolding profiles were observed. Thus, it may be concluded that the two spectrophotometric techniques are sensitive to different BAL chromophores or levels of structural organisation.In a solvent containing calcium (0·1 m Tris-HCl buffer, pH 7·0; 9 mm calcium chloride) there was an increase in the molar UV difference absorbance change associated with GnHCl unfolding of BAL. Unfolding profiles were also biphasic, i.e. denaturation occurred in two stages at different GnHCl concentrations. This pattern of unfolding is different from the usual S-shaped profiles recorded for the three- or two-state BAL unfolding reaction. The results suggest that BAL possesses a more compact structure in the presence of calcium ions. The biphasic transition may arise from the loss of structure, which is unique to calcium-stabilised BAL.

Item Type:Journal article
Faculties and Schools:Faculty of Life and Health Sciences
Faculty of Life and Health Sciences > School of Biomedical Sciences
Research Institutes and Groups:Biomedical Sciences Research Institute
Biomedical Sciences Research Institute > Northern Ireland Centre for Food and Health (NICHE)
ID Code:16953
Deposited By:Dr Richard Owusu-Apenten
Deposited On:01 Feb 2011 13:24
Last Modified:28 Jan 2014 14:46

Repository Staff Only: item control page