passages.id: split_6_test_3212_passage
passages.type: progene_text
passages.text: Tandem mass spectrometry - mass spectrometry ( MS / MS ) analyses of the mutant peptides have revealed that both are shorter variants of 12S globulin with deletion sites detected within the alpha - subunits of 12S globulin cruciferin B ( CRB ) and C ( CRC ) , respectively .