Table I.
Spectral libraries of human peptide sequences used in this study
| SS library | X!Hunter library (xRef) | BiblioSpec library | |
|---|---|---|---|
| Version | IPI v.3.29 | 9/28/2007 | v.23.2, 11/5/2007 |
| Number of spectra | 3,306,625a | 320,658b | 297,519 |
| Number of unique sequences | 1,452,058 | 122,314 | 292,337 |
| Number of ions per spectrum | No limit | Up to 20 | Unknownc |
a
The in silico digested peptide sequences are limited by mass within 900–4500 Da, number of missed cleavages up to 2, charge state up to 3, allowing fixed carbamidomethyl-Cys, and passing missed cleavage rules (14).
b
xRef is managed by protein entry, so the number of spectra may include duplications.
c
The number of ions per spectrum is spectrum-dependent and unknown for entries in the BiblioSpec library.