Methodology Report

Top-Down Proteomic Identification of Furin-Cleaved α-Subunit of Shiga Toxin 2 from Escherichia coli O157:H7 Using MALDI-TOF-TOF-MS/MS

Table 1

The top identifications of the protein biomarker ion at 𝑚 / 𝑧 5286 analyzed by MALDI-TOF-TOF-MS/MS (Figure 3) and top-down proteomics.

RankIn silico ID IdentifierSample name ProteinUSDA scoreP-value

86486>tr∣Q7DI68∣Q7DI68_ECO57Escherichia coli O157:H7Shiga toxin 2 α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86481>tr∣C6UP09∣C6UP09_ECO5TEscherichia coli O157:H7 (strain TW14359/EHEC)Shiga toxin II α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86490>tr∣Q7B5L0∣Q7B5L0_ECOLXEscherichia coli O157:HnegShiga toxin 2 α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86517>tr∣Q6YII8∣Q6YII8_ECOLXEscherichia coli O157:HnegShiga toxin 2 α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86463>tr∣B3VKH7∣B3VKH7_ECOLXEscherichia coliShiga toxin 2 α-subunit (furin-cleaved sequence)
MW = 5284.9
42.372.2E−13
86464>tr∣C5J4Y3∣C5J4Y3_ECOLXEscherichia coliShiga toxin 2 α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
186467>tr∣Q5WPW9∣Q5WPW9_ECOLXEscherichia coliShiga toxin 2 α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86468>tr∣Q8KU16∣Q8KU16_ECOLXEscherichia coliShiga toxin 2 α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86469>tr∣Q8XBV2∣Q8XBV2_ECOLXEscherichia coliShiga toxin 2 α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86473>tr∣B3VKI5∣B3VKI5_ECOLXEscherichia coliShiga toxin 2 α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86474>tr∣B2MW60∣B2MW60_ECOLXEscherichia coliShiga toxin 2 α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86478>tr∣C7FPV8∣C7FPV8_ECOLXEscherichia coliShiga toxin 2 α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86480>tr∣Q47636∣Q47636_ECOLXEscherichia coliShiga toxin 2 α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86472>tr∣Q1ELX7∣Q1ELX7_ECOLXEscherichia coli O111:NMShiga toxin II α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86483>tr∣Q2L9B4∣Q2L9B4_ACIHAAcinetobacter haemolyticusShiga toxin II α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
50965>sp∣P09385∣STXA_BP933Enterobacteria phage 933WShiga-like toxin 2 α-sub. (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86458>sp∣P09385∣STXA_BP933Enterobacteria phage 933WShiga-like toxin 2 α-sub. (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86459>tr∣Q776E1∣Q776E1_9CAUDStx2 converting phage IIShiga toxin 2 α-subunit (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86491>tr∣Q776Q3∣Q776Q3_BPVT2Enterobacteria phage VT2-SaShiga-like toxin 2 α-sub. (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86494>tr∣Q77CH9∣Q77CH9_9VIRUEnterobacteria phage LC159Shiga-like toxin 2 α-sub. (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86499>tr∣Q77CH6∣Q77CH6_9VIRUEnterobacteria phage SC370Shiga-like toxin 2 α-sub. (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86503>tr∣Q6DWK9∣Q6DWK9_9VIRUEnterobacteria phage A397Shiga-like toxin 2 α-sub. (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86518>tr∣Q08JA4∣Q08JA4_9CAUDStx2-converting phage 86Shiga-like toxin 2 α-sub. (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86519>tr∣B0FEE0∣B0FEE0_9CAUDEnterobacteria phage Min27Shiga-like toxin 2 α-sub. (furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13
86520>tr∣Q776G1∣Q776G1_9CAUDStx2 converting phage IShiga toxin 2 α-sub.
(furin-cleaved sequence)
M W = 5 2 8 4 . 9
42.372.2E−13

266935>tr∣A1AXT4∣A1AXT4_RUTMCRuthia magnifica sub. Calyptogena magnifica 50S ribosomal protein L34 PTM-Met
M W = 5 2 8 0 . 3
24.58
79662>tr∣B1C7H9∣B1C7H9_9FIRMAnaerofustis stercorihominis DSM 17244Putative uncharacterized protein
M W = 5 2 8 3 . 4 9
1.2E−3

268014>tr∣A7FRA0∣A7FRA0_CLOB1Clostridium botulinum (strain ATCC 19397/Type A)Bacteriophage prototoxin, streptolysin S family PTM-Met M W = 5 2 8 4 . 9 3 24.58
366935>tr∣A1AXT4∣A1AXT4_RUTMCRuthia magnifica sub. Calyptogena magnifica 50S ribosomal protein L34 PTM-Met
M W = 5 2 8 0 . 3
1.4E−3

268024>tr∣A7G124∣A7G124_CLOBHClostridium botulinum (strain Hall/ATCC 3502/NCTC 13319/Type A)Bacteriophage prototoxin, streptolysin S family PTM-Met M W = 5 2 8 4 . 9 3 24.58
476887>tr∣Q73I98∣Q73I98_WOLPMWolbachia pipientis wMelPutative uncharacterized protein PTM-Met
M W = 5 2 8 5 . 2
3.9E−3

268030>tr∣A7GAP1∣A7GAP1_CLOBLClostridium botulinum (strain Langeland/NCTC 10281/Type F)Bacteriophage prototoxin, streptolysin S family PTM-Met M W = 5 2 8 4 . 9 3 24.58
567756>tr∣A5ZL78∣A5ZL78_9BACEBacteroides caccae ATCC 43185Putative uncharacterized protein PTM-Met
M W = 5 2 7 8 . 6 7
5.2E−3

269116>tr∣B1IEJ6∣B1IEJ6_CLOBKClostridium botulinum (strain Okra/Type B1)Bacteriophage prototoxin, streptolysin S family PTM-Met M W = 5 2 8 4 . 9 3 24.58
575125>tr∣D1P267∣D1P267_9ENTRProvidencia rustigianii DSM 4541Putative uncharacterized protein PTM-Met
M W = 5 2 8 7 . 4
5.2E−3

Comparison parameters: minimum intensity threshold: 2; fragment ion tolerance in m/z: ±1.5; protein mass tolerance: ±10 Da; number of MS/MS above minimum intensity threshold: 118; non-residue-specific in silico comparison; 3833 bacterial protein sequences compared. Algorithm computation times: USDA score 84 seconds, P-value 654 seconds.