These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Denaturation of bovine beta-lactoglobulin in the presence of n-octyl-, decyl-, and dodecyldimethylphosphine oxides.
    Author: Kresheck GC.
    Journal: J Phys Chem B; 2007 Apr 05; 111(13):3550-7. PubMed ID: 17388510.
    Abstract:
    Denaturation of bovine beta-lactoglobulin (beta-L) in pH 2.9, 0.2 M glycine buffer was investigated by DSC in the presence of three nonionic surfactants, n-octyldimethylphosphine oxide (APO8), n-decyldimethylphosphine oxide (APO10), and n-dodecyldimethylphosphine oxide (APO12), and by ITC at temperatures from 25 to 61 degrees C. The thermal transition was eliminated when the molar ratio of surfactant to beta-L was between 88 and 133, 21-25, and 11-22 depending upon the protein concentration for APO8, APO10, and APO12, respectively. A protocol was developed that may be used for future studies that involve ligands with large temperature-dependent heats of dilution. Approximately 30 mol of APO10 and APO12 per mole of beta-L were bound at 45 degrees C and 37 degrees C, respectively, with an average affinity of (2.5 +/- 0.7) x 10(3) M(-1). This amount of surfactant would cover about 50% of the protein surface and may correspond to a new class of nonspecific neutral ligand binding sites that facilitate the digestion of lipids by neonatal calves. Titration of beta-L into 2% solutions of APO8, APO10, and APO12 at various temperatures between 25 and 61 degrees C yielded enthalpy changes with the same temperature dependence as for the thermal denaturation of beta-L without surfactant at much higher temperatures.
    [Abstract] [Full Text] [Related] [New Search]