In total, 30 µg of protein extract was denaturated with 200 µL 8M urea on Microcon YM-30 (#MRCF0R030, Merck KGaA, Darmstadt, Germany) according to Wisniewski et al., in 2009 (FASP protocol), followed by reduction, alkylation and trypsin digestion as described in Frøyset et al. (2016) [29 (link)]
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