Unfolding and refolding of bovine serum albumin induced by cetylpyridinium bromide.
The interaction of bovine serum albumin (BSA) with cationic surfactant cetylpyridinium bromide (CPB) in aqueous solution (pH 7.00) was studied quantitatively with ultraviolet (UV)-visible, far-UV, and near-UV circular dichroism, fluorescence, small angle x-ray scattering, and nuclear magnetic resonance measurement. It was found that CPB at low and high concentrations could induce the unfolding and refolding of BSA, respectively. We suggest that in the unfolding process, there existed BSA-CPB complex with the "necklace and bead" structure in which the unfolded BSA wrapped around CPB micelles, and that the hydrophobic interaction between the complexes led to the formation of large aggregates. The aromatic headgroup of CPB interacted with the tryptophan residues of BSA, resulting in the aromatic ring stacking between BSA and CPB. During the refolding process, the BSA molecule was penetrated into the rod micelle of CPB and the hydrophobic moiety of the BSA molecule was exposed outside while its hydrophilic part was hidden inside, thereby disrupting the aromatic ring stacking.
Sun
Changxia
C
Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
Yang
Jinghe
J
Wu
Xia
X
Huang
Xirong
X
Wang
Fei
F
Liu
Shufang
S
D000818:Animals; D001965:Bromides / Q000737:chemistry / Q000494:pharmacology*; D002412:Cations; D002417:Cattle; D002594:Cetylpyridinium / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D002942:Circular Dichroism; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D008958:Models, Molecular; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D020673:Protein Renaturation; D012542:Scattering, Radiation; D012709:Serum Albumin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D013501:Surface-Active Agents / Q000737:chemistry / Q000494:pharmacology; D014364:Tryptophan / Q000737:chemistry; D014466:Ultraviolet Rays; D014965:X-Rays
D001965:Bromides; D002412:Cations; D008823:Micelles; D012709:Serum Albumin; D013501:Surface-Active Agents; D014364:Tryptophan; D002594:Cetylpyridinium
Biochemistry. 1999 Sep 21;38(38):12313-9
10493799
Biochim Biophys Acta. 1993 Jan 15;1161(1):79-84
8422422
Biochemistry. 1976 Sep 21;15(19):4264-72
963036
Cell Motil Cytoskeleton. 2003 Jan;54(1):16-28
12451592
Biochim Biophys Acta. 1997 Apr 4;1338(2):161-85
9128135
J Biochem. 1974 Feb;75(2):309-19
4837445
J Biol Chem. 1970 Oct 10;245(19):5161-5
5528242
Proc Natl Acad Sci U S A. 1970 Jul;66(3):1002-7
5269225
J Biol Chem. 1974 Jul 25;249(14):4452-9
4210504
J Biol Chem. 2000 Feb 4;275(5):3042-50
10652284
J Mol Biol. 1998 Dec 4;284(3):761-77
9826514
Curr Opin Biotechnol. 1995 Feb;6(1):103-10
7534502
Phys Rev Lett. 1986 Nov 17;57(20):2583-2586
10033804
Eur J Biochem. 1990 Jun 20;190(2):311-8
2194800
Environ Health Perspect. 2002 Oct;110 Suppl 5:733-8
12426122
Guang Pu Xue Yu Guang Pu Fen Xi. 2000 Jun;20(3):427-30
12958980
J Am Chem Soc. 2002 Mar 13;124(10):2104-5
11878950
Biotechnol Appl Biochem. 2000 Feb;31(1):29-40
10669400
Biochim Biophys Acta. 2002 Jan 31;1594(1):84-99
11825611
Biochem J. 1975 Oct;151(1):109-14
1212210