Protein-phenolic interaction of tryptic digests of β-lactoglobulin and cloudberry ellagitannin.
LC-ESI-MS was applied to investigate interaction reactions between a dimeric ellagitannin, sanguiin H-6, isolated from cloudberries (Rubus chamaemorus) and peptides of β-lactoglobulin (β-Lg). Three peptides, LIVTQTMK (m/z 934), ALPMHIR (m/z 838), and IPAVFK (m/z 674) were isolated from enzymatic (trypsin) digestion of β-Lg. Oxidation of the peptides with and without sanguiin H-6 was monitored by LC-ESI-MS for up to 7 days. Sanguiin H-6 showed radical scavenging activities toward oxidation of the selected peptides. An interaction product was found with sanguiin H-6 and peptide LIVTQTMK by using MS and supported by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). An observable (haze) but unstable interaction product of sanguiin H-6 was seen with peptide ALPMHIR, but no detectable interaction products were seen with peptide IPAVFK. A higher proportion of sanguiin H-6 toward the amount of peptide might allow for further characterization of these interaction products.
Department of Food and Environmental Sciences, Division of Food Chemistry, University of Helsinki , P.O. Box 27, FI-00014 University of Helsinki, Finland.
Bei
B
Wang
Tuuli
T
Koivumäki
Petri
P
Kylli
Marina
M
Heinonen
Marjo
M
Poutanen
D000818:Animals; D002417:Cattle; D002853:Chromatography, Liquid; D004063:Digestion; D047348:Hydrolyzable Tannins / Q000737:chemistry*; D007782:Lactoglobulins / Q000737:chemistry*; D013058:Mass Spectrometry; D010636:Phenols / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D065856:Rubus / Q000737:chemistry*; D014357:Trypsin / Q000737:chemistry
D047348:Hydrolyzable Tannins; D007782:Lactoglobulins; D010636:Phenols; D010936:Plant Extracts; C013515:ellagitannin; D014357:Trypsin