Identification of filaggrin as the protein absent in Matriptase/MT-SP1–deficient skin by mass spectrometry
Measured mass . | Theoretical massa . | Residue no. . | Sequence . |
|---|---|---|---|
| D | D | ||
| 2461.4 | 2461.5 | 117–136 | (R)GHQHQHQHQHEHEQPESGHR(Q) |
| 2197.1 | 2197.3 | 206–226 | (R)QPSPSQSSDSQVHSGVQVEGR (R) |
| 2354.3 | 2353.5 | 206–227 | (R)QPSPSQSSDSQVHSGVQVEGRR (G) |
| 2721.9 | 2721.5 | 202–226 | (R)DRPRQPSPSQSSDSQVHSGVQVEGR (R) |
| 2632.6 | 2632.6 | 45–70 | (R)GVSESQASDSEGHSDFSEGQAVGAHR (Q) |
| 2788.2 | 2788.8 | 44–70 | (R)RGVSESQASDSEGHSDFSEGQAVGAHR(Q) |
Measured mass . | Theoretical massa . | Residue no. . | Sequence . |
|---|---|---|---|
| D | D | ||
| 2461.4 | 2461.5 | 117–136 | (R)GHQHQHQHQHEHEQPESGHR(Q) |
| 2197.1 | 2197.3 | 206–226 | (R)QPSPSQSSDSQVHSGVQVEGR (R) |
| 2354.3 | 2353.5 | 206–227 | (R)QPSPSQSSDSQVHSGVQVEGRR (G) |
| 2721.9 | 2721.5 | 202–226 | (R)DRPRQPSPSQSSDSQVHSGVQVEGR (R) |
| 2632.6 | 2632.6 | 45–70 | (R)GVSESQASDSEGHSDFSEGQAVGAHR (Q) |
| 2788.2 | 2788.8 | 44–70 | (R)RGVSESQASDSEGHSDFSEGQAVGAHR(Q) |
Theoretical average masses were derived from the National Center for Biotechnology Information database identifying mouse filaggrin B (GenBank/EMBL/DDBJ accession no. B35026).
Skin lysates from newborn Matriptase/MT-SP1−/− mice and littermate controls were separated by SDS-PAGE, and proteins were stained with amido black. Two corresponding gel pieces, in the region where a major protein appeared to be absent in the Matriptase/MT-SP1−/− mice, were excised from parallel lanes containing skin lysates from Matriptase/MT-SP1−/− mice and control mice, and were subjected to in-gel trypsin digestion. The fragments listed represent peptides that were prominent in the control skin and were nondetectable in the Matriptase/MT-SP1−/− skin.