Quantitative assessment of thermal denaturation of bovine alpha-lactalbumin via low-intensity ultrasound, HPLC, and DSC.
The degree of irreversible aggregation and the aggregation velocity constant of alpha-lactalbumin (alpha-la) were determined by three methods based on different principles: low-intensity ultrasound as a novel method for this purpose, DSC, and HPLC. The denaturation process of alpha-la causes a decrease in the ultrasonic velocity due to the conformation change of alpha-la molecules. This decrease is a function of the concentration of native alpha-la in the sample. A linear correlation was found between the degree of aggregation of alpha-la determined by these three methods. There is no significant difference between the aggregation velocity constants determined by the three methods. The results show that the ultrasonic method is capable of quantifying the degree of aggregation of a protein, offering an alternative method.
Wang
Qin
Q
Chair for Food Process Engineering and Dairy Technology, Technische Universität München, 85354 Freising-Weihenstephan, Germany. qin.wang@wzw.tum.de
Tolkach
Alexander
A
Kulozik
Ulrich
U
D000818:Animals; D002152:Calorimetry, Differential Scanning; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D006358:Hot Temperature; D007700:Kinetics; D007768:Lactalbumin / Q000737:chemistry*; D011489:Protein Denaturation; D014465:Ultrasonics
D007768:Lactalbumin