Association behavior of native ?-lactoglobulin

Verheul, Marleen; Pedersen, Jan Skov; Roefs, S.P.F.M.; Kruif, Kees G. de

doi:10.1002/(sici)1097-0282(199901)49:1<11::aid-bip2>3.0.co;2-1

Cited by 195 publications

(194 citation statements)

References 40 publications

Supporting

Mentioning

180

Contrasting

Unclassified

Order By: Relevance

“…Attractive forces emerged around these pH values could generate aggregates. These forces may be attributed to hydrophobic attractive forces, electrostatic and van der Waals forces (Verheul et al, 1999). Only particle sizes below one micron are taken into account in the turbidity measurement as demonstrated by Xu et al (2006).…”

Section: Discussionmentioning

confidence: 99%

Whey proteins analysis in aqueous medium and in artificial gastric and intestinal fluids

Gbassi¹,

Yolou²,

Sarr³

et al. 2012

Int. J. Bio. Chem. Sci

View full text Add to dashboard Cite

Whey proteins isolates (WPI) were treated in aqueous medium at various pH values. Zeta potential, turbidity and particle size measurement were determined as a function of pH. FTIR analysis was performed in ATR mode (attenuated total reflectance). Digestibility was assessed by treating whey proteins with artificial gastric and intestinal fluids. Proteolytic enzymes such as pepsin from porcine stomach mucosa was added in the gastric fluid. Pancreatin and trypsin from porcine and bile salts were added in the intestinal fluid. SDS-PAGE revealed hydrolysis of α-lactalbumin and bovine serum albumin by pepsin while β-lactoglobulin was not hydrolyzed by gastric fluid. All the proteins of WPI were easily hydrolyzed in the intestinal fluid. The zeta potential of WPI went from positive values to negative values as the pH was increased. Turbidity values indicated the presence of particles in the solution which were confirmed by the measurement of particle size. FTIR analysis determined the fingerprint of WPI macromolecule.

show abstract

Section: Discussionmentioning

confidence: 99%

Whey proteins analysis in aqueous medium and in artificial gastric and intestinal fluids

Gbassi¹,

Yolou²,

Sarr³

et al. 2012

Int. J. Bio. Chem. Sci

View full text Add to dashboard Cite

show abstract

“…In fact, we have shown that the affinities of ANS for the two sites, referred to as "site 1," longer decay time, and "site 2," shorter lifetime decay, appear to be of comparable strength since a substantial weight for both lifetimes is always detected when performing ANS titrations on a wide range of protein concentrations~2 mM-10 mM! at pH 2, pH 6 and pH 8, corresponding to different degrees of dimerization~Townend et al, 1960;Verheul et al, 1999!. The lifetime values were found to be constant during the titration and the fractional intensities followed a simple mass-action law.…”

Section: Lifetimesmentioning

confidence: 99%

New insight on β‐lactoglobulin binding sites by 1‐anilinonaphthalene‐8‐sulfonate fluorescence decay

2000

View full text Add to dashboard Cite

The fluorescence time decay parameters of the b-lactoglobulin-1-anilinonaphthalene-8-sulfonate complex have been investigated under physical and chemical perturbations~2 Ͻ pH Ͻ 8 and added electrolyte 0 Ͻ NaCl Ͻ 0.5 M! to obtain new insight on the nature of the protein binding interactions. A double exponential decay of the bound probe lifetime has been confirmed by the presence of a longer component, 11 to 14.5 ns, and a shorter component, 2.5 to 3.5 ns. The two lifetimes are ascribed to different binding modes associated also with different exposure to the solvent; in particular, the longer component is attributed to binding inside the hydrophobic beta barrel, while a "surface" site is suggested for the shorter component. A detailed analysis of the lifetime fractional intensities correlates the binding constants with ionic strength and supports the presence of electrostatic effects at both sites. A Debye-Hückel approach, applied to extrapolate the electrostatic free energy contribution vs. pH at vanishing ionic strength, gives interesting clues on the effective charge felt by the ANS ligands in the proximity of each site. In particular, binding is found to parallel the aspartate and glutamate titrations between pH 3 and pH 4.5; the "surface" site mainly responds to the presence of these local titrating charges while the "internal" site more closely follows the overall protein net charge.Keywords: ANS; b-lactoglobulin; binding sites; electrostatic interactions b-Lactoglobulin, a 162 residues globular protein whose proper functionality has not been clarified yet, in spite of the great number of studies performed on this protein, is present in very large quantities in the milk of several mammals, thus suggesting its nutritional role. Its interaction with a great variety of hydrophobic ligands, such as retinol~Futterman & Heller, 1972;Dufour et al., 1990;Dufour & Haertlé, 1991;Cho et al., 1994;Narayan & Berliner, 1997; Lange et al., 1998!, fatty acids and triglycerides~Du-four et al., 1990;Frapin et al., 1993;Narayan & Berliner, 1997;Qin et al., 1998b;Wu et al., 1999!, has led to its inclusion in the lipocalin superfamily~Brownlow et al., 1997!. This family includes transport proteins, such as the retinol binding protein, the odorant binding protein, and the major urinary protein, which all share the common structural feature of a b-barrel calyx, built from eight antiparallel b-sheets, arranged as an ideal site for hydrophobic ligands~Brownlow et al., 1997!.Since b-lactoglobulin appears to lack specificity for particular ligands and since several studies suggest that more than one binding site exists, it seems interesting to further investigate the nature and the general features of the protein binding sites. A thorough study is carried out here with a "test" ligand, ANS, a molecule that shares both hydrophilic and hydrophobic characters and whose fluorescence response appears as a convenient and sensitive tool apt to investigate the nature of b-lactoglobulin binding regions. While ANS is only weakly fluor...

show abstract

“…Under these conditions beta-lactoglobulin aggregates much faster and alpha-crystallin is not a good chaperone [25] to prevent its aggregation. At room temperature and physiological pH, betalactoglobulin exists as a dimer in which the monomers are noncovalently linked but dissociates into monomers upon heating [33] . beta-lactoglobulin undergoes heatinduced structural changes, which involve the exposure of buried hydrophobic groups and thiol groups [34] .…”

Section: Discussionmentioning

confidence: 99%

The Effect of Molecular Chaperone, Alpha-Crystallin, on the Heat-Induced Aggregation of Beta-lactoglobulin

Ghahghaei¹

2008

American J. of Biochemistry and Biotechnology

View full text Add to dashboard Cite

Aggregation of beta-lactoglobulin occurs mainly via intermolecular disulphide bond exchange. Upon heating, beta-lactoglobulin aggregated which increased with increasing pH. The presence of DTT led to more rapid aggregation and precipitation of beta-lactoglobulin. AlphaCrystallin prevented the aggregation of heat-stressed beta-lactoglobulin and was a more efficient chaperone at higher pH values. In the presence of DTT, however, alpha-crystallin was a less efficient chaperone due to faster aggregation of heated and reduced beta-lactoglobulin.

show abstract

Association behavior of native ?-lactoglobulin

Cited by 195 publications

References 40 publications

Whey proteins analysis in aqueous medium and in artificial gastric and intestinal fluids

Whey proteins analysis in aqueous medium and in artificial gastric and intestinal fluids

New insight on β‐lactoglobulin binding sites by 1‐anilinonaphthalene‐8‐sulfonate fluorescence decay

The Effect of Molecular Chaperone, Alpha-Crystallin, on the Heat-Induced Aggregation of Beta-lactoglobulin

Contact Info

Product

Resources

About