A study of alcohol-induced gelation of β-lactoglobulin with small-angle neutron scattering, neutron spin echo, and dynamic light scattering measurements

被引:18
作者
Yoshida, Koji [1 ,2 ]
Yamaguchi, Toshio [1 ,2 ]
Osaka, Noboru [3 ]
Endo, Hitoshi [3 ]
Shibayama, Mitsuhiro [3 ]
机构
[1] Fukuoka Univ, Adv Mat Inst, Jonan Ku, Fukuoka 8140180, Japan
[2] Fukuoka Univ, Dept Chem, Fac Sci, Fukuoka 8140180, Japan
[3] Univ Tokyo, Inst Solid State Phys, Kashiwa, Chiba 2778581, Japan
关键词
PRESSURE-INDUCED GELATION; ALPHA-HELIX FORMATION; INDUCED DENATURATION; MOLECULAR-DYNAMICS; AQUEOUS-SOLUTIONS; GLOBULAR PROTEIN; SANS-U; TRIFLUOROETHANOL; PEPTIDES; WATER;
D O I
10.1039/b920187d
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Gelation of beta-lactoglobulin (beta-Lg) in various alcohol-water mixtures with 0.1 M (M = mol L-1) hydrochloric acid was investigated with small-angle neutron scattering (SANS), neutron spin echo (NSE), and time-resolved dynamic light scattering (TRDLS) measurements. The beta-Lg in alcohol-water solutions undergoes gelation at specific alcohol concentrations where the alcohol-induced a-helical structure of beta-Lg is stabilized. The SANS profiles showed that beta-Lg exists as a single molecule at a low alcohol concentration. With increasing alcohol concentration, the profiles indicate a power law behavior of similar to 1.7 when the samples gelate. These behaviors were observed in all alcohol-water mixtures used, but the alcohol concentrations where the SANS profiles change shift to a lower alcohol concentration region with an increase in the size of the hydrophobic group of the alcohols. Apparent diffusion constants, obtained from the intermediate scattering function (ISF) of NSE and the intensity time correlation function (ITCF) of TRDLS, mainly depend on the viscosity of alcohol-water mixtures before gelation. After gelation, on the other hand, the ISFs of gels do not change appreciably in the range of the NSE time scale, indicating the microscopically rigid structure of beta-Lg gel. The ITCF functions obtained from TRDLS follow a double exponential decay type before gelation, but a logarithmic one (exponent alpha = 0.7) after gelation. It is most likely that the alcohol-induced gelation undergoes a similar mechanism to that for the heat-induced one at pH = 7 where beta-Lg aggregates stick together to form a fractal network, although the gelation time is faster in the former than in the latter.
引用
收藏
页码:3260 / 3269
页数:10
相关论文
共 48 条
[1]   Influence of cosolvent systems on the gelation mechanism of globular protein: Thermodynamic, kinetic, and structural aspects of globular protein gelation [J].
Baier, SK ;
McClements, DJ .
COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, 2005, 4 (03) :43-54
[2]   New stable folding of β-lactoglobulin induced by 2-propanol [J].
Barteri, M ;
Gaudiano, MC ;
Giampiero, M ;
Rosato, N .
BIOCHIMICA ET BIOPHYSICA ACTA-PROTEIN STRUCTURE AND MOLECULAR ENZYMOLOGY, 1998, 1383 (02) :317-326
[3]   Main-chain dynamics of a partially folded protein: N-15 NMR relaxation measurements of hen egg white lysozyme denatured in trifluoroethanol [J].
Buck, M ;
Schwalbe, H ;
Dobson, CM .
JOURNAL OF MOLECULAR BIOLOGY, 1996, 257 (03) :669-683
[4]   Trifluoroethanol and colleagues: cosolvents come of age. Recent studies with peptides and proteins [J].
Buck, M .
QUARTERLY REVIEWS OF BIOPHYSICS, 1998, 31 (03) :297-355
[5]   Protein misfolding, functional amyloid, and human disease [J].
Chiti, Fabrizio ;
Dobson, Christopher M. .
ANNUAL REVIEW OF BIOCHEMISTRY, 2006, 75 :333-366
[6]   Small-angle neutron scattering study of structure and kinetics of temperature-induced protein gelation [J].
Chodankar, S. ;
Aswal, V. K. ;
Kohlbrecher, J. ;
Vavrin, R. ;
Wagh, A. G. .
PHYSICAL REVIEW E, 2009, 79 (02)
[7]   Lysozyme gelation in mixtures of tetramethylurea with protic solvents:: Use of solvatochromic indicators to probe medium microstructure and solute-solvent interactions [J].
da Silva, Marcelo A. ;
El Seoud, Omar A. ;
Areas, Elizabeth P. G. .
JOURNAL OF MOLECULAR STRUCTURE, 2007, 841 (1-3) :51-60
[8]   Infrared and circular dichroism spectroscopic characterization of structural differences between beta-lactoglobulin A and B [J].
Dong, A ;
Matsuura, J ;
Allison, SD ;
Chrisman, E ;
Manning, MC ;
Carpenter, JF .
BIOCHEMISTRY, 1996, 35 (05) :1450-1457
[9]   Protein-water displacement distributions [J].
Doster, W ;
Settles, M .
BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS, 2005, 1749 (02) :173-186
[10]   Solvation phenomena of a tetrapeptide in water/trifluoroethanol and water/ethanol mixtures: A diffusion NMR, intermolecular NOE, and molecular dynamics study [J].
Fioroni, M ;
Diaz, MD ;
Burger, K ;
Berger, S .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2002, 124 (26) :7737-7744