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PXD016770 is an original dataset announced via ProteomeXchange.

Dataset Summary
TitleGeneration of aggregates of alpha-lactalbumin by UV-B light exposure
DescriptionWhey proteins are widely used as ingredients in the form of aggregates to obtain certain functionalities in food applications. The aim of this study was to understand how UV illumination generates aggregates of ?-lactalbumin (?-LA) as an alternative to heat treatments traditionally used for industrial production of protein aggregates. Absorption of UV light by ?-LA caused cleavage of disulfide bonds and release of thiol groups, which resulted in primarily disulfide-mediated aggregation. This process mediated efficient aggregation with up to 98% monomer conversion into aggregates through formation of intermolecular disulfide bonds, while only minor levels of nonreducible cross-links were observed. SDS-PAGE analysis revealed that illumination led to formation of dimeric, trimeric, and oligomeric forms of ?-LA. LC-MS/MS analysis showed that all of the four native disulfide bonds in ?-LA were cleaved by UV illumination but to different extents, and the extent of cleavage was found to be higher in the absence of calcium. Seventeen different non-native disulfides were formed after 24 h of UV illumination. Two dityrosine bonds were identified (Tyr103-Tyr103 and Tyr36-Tyr103) alongside ditryptophan (Trp118-Trp118) and tyrosine-tryptophan (Tyr50-Trp60) cross-links. In addition, Trp60, Trp118, Cys73, Cys91, Cys120, Phe80, Met90, His68, and His107 were found to be oxidized up to 12% as compared to a nonilluminated control. Our work illustrates that light exposure can be used for generation of ?-LA aggregates, but optimization of the illumination conditions is required to reduce oxidative damage to Trp, Cys, Phe, Met, and His residues.
ReviewLevelNon peer-reviewed dataset
DatasetOriginOriginal dataset
RepositorySupportUnsupported dataset by repository
PrimarySubmitterKasper Engholm-Keller
SpeciesList scientific name: Bos taurus; common name: cattle; NCBI TaxID: 9913;
ModificationListOxidation; Dioxidation; Trioxidation; Cys->Dha; Trp->Kynurenin; Homocysteic_acid; Dethiomethyl; Deamidated; 3'-(3'-L-tyrosinyl)-L-tyrosine; L-cystine (cross-link)
InstrumentQ Exactive
Dataset History
RevisionDatetimeStatusChangeLog Entry
02019-12-16 01:54:57ID requested
12020-05-22 02:51:12announced
Publication List
no publication
Keyword List
submitter keyword: alpha lactalbumin, UV, aggregation, disulfide, modification, whey, Illumination
Contact List
Marianne Nissen Lund
contact affiliationDepartment of Food Science, University of Copenhagen
contact emailmnl@food.ku.dk
lab head
Kasper Engholm-Keller
contact affiliationUniversity of Copenhagen
contact emailkasperengholmkeller@gmail.com
dataset submitter
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