TY - JOUR
T1 - Thermodynamic analysis of the effect of calcium on bovine alpha-lactalbumin conformational stability
AU - Owusu, Richard
PY - 1992
Y1 - 1992
N2 - ΔG° Values for bovine alpha-lactalbumin (BAL) unfolding in a range of solvents, including simulated milk ultrafiltrate buffer, were determined. The denaturant used was guanidine hydrochloride. In Ca2+-free solvents fluorescence and ultraviolet (UV) difference absorbance unfolding profiles were non-superimposable leading to ΔG° estimates of 15–17 kJ mol−1 and 21–28 kJ mol−1, respectively. Therefore, the unfolding of BAL was consistent with a three-state reaction. The low and high ΔG° estimates may correspond to the loss of BAL 3° and 2° structure, respectively.The presence of excess Ca2+, two BAL unfolding transitions (I and II) were observed with both spectrophotometric techniques. Transition (II) was associated with a ΔG° value of 52 kJ mol− and is probably identical to a two-state BAL unfolding reaction described previously. Transition (I) appears to signify a novel feature of BAL structure.
AB - ΔG° Values for bovine alpha-lactalbumin (BAL) unfolding in a range of solvents, including simulated milk ultrafiltrate buffer, were determined. The denaturant used was guanidine hydrochloride. In Ca2+-free solvents fluorescence and ultraviolet (UV) difference absorbance unfolding profiles were non-superimposable leading to ΔG° estimates of 15–17 kJ mol−1 and 21–28 kJ mol−1, respectively. Therefore, the unfolding of BAL was consistent with a three-state reaction. The low and high ΔG° estimates may correspond to the loss of BAL 3° and 2° structure, respectively.The presence of excess Ca2+, two BAL unfolding transitions (I and II) were observed with both spectrophotometric techniques. Transition (II) was associated with a ΔG° value of 52 kJ mol− and is probably identical to a two-state BAL unfolding reaction described previously. Transition (I) appears to signify a novel feature of BAL structure.
U2 - 10.1016/0308-8146(92)90186-6
DO - 10.1016/0308-8146(92)90186-6
M3 - Article
VL - 44
SP - 189
EP - 194
JO - Food Chemistry
JF - Food Chemistry
SN - 0308-8146
IS - 3
ER -