Department of Food and Environmental Sciences, Division of Food Chemistry, University of Helsinki , P.O. Box 27, FI-00014 University of Helsinki, Finland.
J Agric Food Chem. 2014 Jun 4;62(22):5028-37. doi: 10.1021/jf501190x. Epub 2014 May 27.
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.
LC-ESI-MS 被应用于研究从云莓（Rubus chamaemorus）中分离出的二聚鞣花单宁酸、桑辛 H-6 与β-乳球蛋白（β-Lg）肽之间的相互作用反应。从β-Lg 的酶解（胰蛋白酶）中分离出了三个肽，LIVTQTMK（m/z 934）、ALPMHIR（m/z 838）和 IPAVFK（m/z 674）。用 LC-ESI-MS 监测了有和没有桑辛 H-6 存在时肽的氧化情况，最长达 7 天。桑辛 H-6 对所选肽的氧化表现出自由基清除活性。通过 MS 发现了桑辛 H-6 与 LIVTQTMK 肽的相互作用产物，并通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）得到支持。虽然可以看到与肽 ALPMHIR 之间存在可观察到的（浑浊）但不稳定的相互作用产物，但与肽 IPAVFK 之间未检测到相互作用产物。如果桑辛 H-6 与肽的比例更高，可能会进一步表征这些相互作用产物。
