passages.id: split_1_test_1557_passage
passages.type: progene_text
passages.text: Matrix assisted laser desorption ionization mass spectrometry ( MALDI - MS ) of the tryptic digests of these proteins , identified one as the 86 kDA Lupus KU autoantigen protein P86 and the second as the 70 kDa Lupus KU autoantigen protein P70 .