A Recombinant C121S Mutant of Bovine β-Lactoglobulin Is More Susceptible to Peptic Digestion and to Denaturation by Reducing Agents and Heating

Jayat, Damien; Gaudin, Jean-Charles; Chobert, Jean‐Marc; Burova, Tatiana V.; Holt, Carl; McNae, I.W.; Sawyer, Lindsay; Haertlé, Thomas

doi:10.1021/bi0362469

Cited by 51 publications

(40 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As discussed earlier, longer heating time provides the time for greater extent of the reactions to happen, in particular for the thiol-disulfide exchange reactions (Livney et al, 2003;Jayat et al, 2004). The disulfide bridges are known to be a key factor that affects the gel strength (Hoffmann and Van Mil, 1999;Creamer et al, 2004) and the aggregation process through the polymerization of monomers to form large polymer chains.…”

Section: Effect Of Heating Time On Hiwpg Dissolutionmentioning

confidence: 99%

Influence of Run Time and Aging on Fouling and Cleaning of Whey Protein Deposits on Heat Exchanger Surface

Fickak¹,

Hatfield

Chen

2012

JFR

View full text Add to dashboard Cite

In the cleaning operations of heat exchange surfaces in dairy processing plants, the effect of heating/run time (HT) and aging on the fouling/cleaning of heat exchangers is not well understood. Longer heating time of the same deposit is expected to result in the formation of stronger and perhaps more cleaning resistant deposit. In this study, the phenomenon of heating and aging on the formation and cleaning of dairy fouling is investigated using the heat induced whey protein gels (HIWPG) produced in laboratory. The processes were also investigated with the whey protein deposits formed in pilot-scale plant trails.The HIWPGs were produced in tubular capsules for various heating (or run) times (60, 120, 240, 1440 and 2880 min respectively) and then dissolved in aqueous sodium hydroxide (0.5 wt %). The heating process here would have been of 'pure' aging. The dissolution rate was calculated based on the previously established UV Spectrophotometer analysis. The structure and texture of the gels were analysed using Scanning Electron Microscope (SEM) and texture analyser. In the pilot-scale plant study, whey protein fouling layers were generated by recirculating whey protein solution (6 wt %) for various heating periods (30, 60, and 90 min respectively). The deposit layers were then removed by recirculating aqueous sodium hydroxide (0.5 wt %) and the cleaning efficiency was monitored in the form of the recovery of heat transfer coefficient while both fluid electric conductivity and turbidity were recorded as indications of cleaning completion. It was found that increasing the HIWPG heating time significantly increased the gel hardness and dissolution time, implicating the difficulty in cleaning. Similarly to these results on gels, increasing the pilot-scale plant heating/run time increased the extent of fouling. The fouling layer formed next to the metal surface experienced the longest period of aging and the slope of the heat transfer coefficient increase seen at the final cleaning stage is related to this aging effect. The rate of cleaning for deposits formed initially on the metal surface is lower indicating a 'pure' aging effect of the deposit near surface.

show abstract

Section: Effect Of Heating Time On Hiwpg Dissolutionmentioning

confidence: 99%

Influence of Run Time and Aging on Fouling and Cleaning of Whey Protein Deposits on Heat Exchanger Surface

Fickak¹,

Hatfield

Chen

2012

JFR

View full text Add to dashboard Cite

show abstract

“…Therefore, limited proteolysis might be a more sensible tool to determine conformational changes of a-lactalbumin than spectroscopic techniques as it has been also reported in the case of b-lactoglobulin modified by site-directed mutagenesis [24].…”

Section: Proteolysis Of A-lactalbumin As a Function Of Ethanol Concenmentioning

confidence: 99%

Study of ethanol‐induced conformational changes of holo and apo α‐lactalbumin by spectroscopy and limited proteolysis

Wehbi¹,

Pérez²,

Dalgalarrondo³

et al. 2006

Molecular Nutrition Food Res

Self Cite

View full text Add to dashboard Cite

This study was performed to contribute to the analysis of alpha-lactalbumin "molten globule" state by using spectral and proteolysis techniques. Samples of holo and apo alpha-lactalbumin in the presence of different concentrations of ethanol were analyzed. Results of fluorescence spectroscopy of both forms showed that as ethanol concentration increased, the tryptophanyl residues became more accessible to the solvent. Near circular dichroism spectra of holo alpha-lactalbumin indicated that its tertiary structure was maintained in 20% ethanol whereas it was altered in 30 and 40% ethanol. For apo alpha-lactalbumin, spectra were similar in all samples studied. Holo alpha-lactalbumin was resistant to trypsinolysis in 0% ethanol, whereas it was easily hydrolyzed in 20 and 30% ethanol. In the case of the apo form and in the absence of ethanol, 70% of the protein was degraded after 1 h. However, in the presence of 20 and 30% ethanol, the overall reaction rate was lowered. Peptides obtained after tryptic hydrolysis were identified by reversed-phase high-performance liquid chromatography coupled to mass spectrometry. Differences in population of produced peptides indicate the changes of folding intermediates present in the studied alpha-lactalbumin solutions. This study demonstrated that proteolytic enzymes are suitable tools to determine protein structure complementing physico-chemical studies.

show abstract

“…β-LG has 5 cysteins, 4 of which forming 2 disulfide bonds. The remaining free thiol group is buried within the protein structure on the β-strand H. The disulfide bonds contribute to the reversible denaturation of β-LG (Kitabatake et al 2001), whereas the free thiol stabilizes the native protein structure (Jayat et al 2004). At room temperature, β-LG exhibits pH-dependent reversible self-association behavior (Yan et al 2013).…”

Section: β-Lactoglobulinmentioning

confidence: 99%

Current ways to modify the structure of whey proteins for specific functionalities—a review

Guyomarc’H

Famelart

Henry

et al. 2014

Dairy Sci. & Technol.

View full text Add to dashboard Cite

The native whey proteins have been intensively used in a multitude of food applications due to their high nutritional, biological, and versatile technofunctional properties. The range of applications of whey proteins has further been extended in the last decades by the use of whey protein aggregates offering new technofunctional properties. These properties are directly dependent on the structure of whey protein aggregates, i.e., their size, shape, density, surface properties, and the type of bonds maintaining proteins together in the aggregates. In this review, after a brief description of the major whey proteins, we examine the most important advances reported to date pertaining to the available approaches to modify the structure of whey proteins for specific functionalities. Our laboratory, Science and Technology of Milk and Eggs, has contributed significantly to the advancement of knowledge on the structure-function relationships of whey proteins either in the native or denatured/aggregated forms. Our expertise and research approaches are highlighted throughout some selected results accumulated during the last decade in comparison with results from the literature.

show abstract

A Recombinant C121S Mutant of Bovine β-Lactoglobulin Is More Susceptible to Peptic Digestion and to Denaturation by Reducing Agents and Heating

Cited by 51 publications

References 55 publications

Influence of Run Time and Aging on Fouling and Cleaning of Whey Protein Deposits on Heat Exchanger Surface

Influence of Run Time and Aging on Fouling and Cleaning of Whey Protein Deposits on Heat Exchanger Surface

Study of ethanol‐induced conformational changes of holo and apo α‐lactalbumin by spectroscopy and limited proteolysis

Current ways to modify the structure of whey proteins for specific functionalities—a review

Contact Info

Product

Resources

About