Table 3 Resolving the OIPs among y10-1+, y20-2+ and y72-7+ in the HCD Spectrum of Myoglobin Using the OIE_CARE Method.*

From: Accurate and Efficient Resolution of Overlapping Isotopic Envelopes in Protein Tandem Mass Spectra

 

A

B

C

D

E

F

G

H

1

    

y10-1+

y20-2+

y72-7+

 

2

  

Exp. m/z

Exp. abun. (observed)

Exp. abun. (ideal)

Exp. abun. (ideal)

Exp. abun. (ideal)

Deviation

3

  

1142.617676

480992.312500

46615.469396

416521.895787

66542.651159

−0.09

4

y10-1+

5

Theo. m/z

Theo. rel. abun.

Exp. m/z

Exp. abun.

Exp. rel. abun.

IPMD

IPAD

IPAD#

6

1141.607714

63.64

1141.613770

128926.921875

63.64

5

0

 

7

1142.610419

23.01

1142.617676

42330.617979

20.89

6

−2

214

8

y20-2+

9

Theo. m/z

Theo. rel. abun.

Exp. m/z

Exp. abun.

Exp. rel. abun.

IPMD

IPAD

IPAD#

10

1142.611961

100.00

1142.617676

378235.583145

90.81

5

−9

15

11

1143.113357

67.65

1143.120117

281777.062500

67.65

6

0

 

12

y72-7+

13

Theo. m/z

Theo. rel. abun.

Exp. m/z

Exp. abun.

Exp. rel. abun.

IPMD

IPAD

IPAD#

14

1142.607764

55.06

1142.617676

60426.111376

50.00

9

−5

343

15

1142.894250

100.00

1142.910522

120854.796875

100.00

14

0

 
  1. For OIP of m/z 1142.617676:
  2. Step 1: The ideal exp. abundance for y10-1+ (E3), y20-2+ (F3) and y72-7+ (G3) is calculated using B7*D6/B6 and B10*D11/B11 and B14*D15/B15, respectively.
  3. Step 2: The deviation (H3) between the observed and ideal values is calculated using (D3 − (E3 + F3 + G3))/(E3 + F3 + G3).
  4. Step 3: The final individual exp. abun. for y10-1+ (D7), y20-2+ (D10) and y72-7+ (D14) is calculated using E3*(1 + H3), F3*(1 + H3), G3*(1 + H3), respectively.
  5. *Only OIP of m/z 1142.617676 and the isotopic peaks used for normalization are listed here. The resolving of the other four OIPs of these three product ions and y144-14+ was performed using the same method. The full iEF information is provided in Table S6.
  6. #The equivalent IPAD values without OIE_CARE. Exp. = experimental, theo. = theoretical and abun. = abundance.