Table 1.
Bruker Reflex Matrix-assisted laser desorption ionization-time of flight mass spectrometer analysis of 55-kDa peptides
| Sequence | Peptide mass, monoisotopic, Da
|
|
|---|---|---|
| Measured | Calculated | |
| QMSLLLR | 859.48 | 859.495 |
| AVDSLVPIGR | 1025.58 | 1025.587 |
| VGLKAPGIIPR | 1119.68 | 1119.713 |
| TIAMDGTEGLVR | 1261.40 | 1261.634 |
| ISVREPMQTGIK | 1357.70 | 1357.739 |
| IMNVIGEPIDER | 1384.68 | 1384.702 |
| AHGGYSVFAGVGER | 1405.66 | 1405.674 |
| FTQAGSEVSALLGR | 1434.73 | 1434.747 |
| TSIAIDTIINQKR | 1471.81 | 1471.836 |
| EAYPGDVPYLHSR | 1552.71 | 1552.731 |
| VALVYGQMNEPPGAR | 1600.79 | 1600.803 |
| TGAIVDVPVGEELLGR | 1623.87 | 1623.883 |
| LVLEVAQHLGESTVR | 1649.88 | 1649.910 |
| IMDPNIVGSEHYDVAR | 1814.85 | 1814.862 |
| VLDSGAPIKIPVGPETLGR | 1918.08 | 1918.089 |
| AIAELGIYPAVDPLDSTSR | 1986.99 | 1987.026 |
| IMNVIGEPIDERGPIKTK | 2009.10 | 2009.098 |
| IPSAVGYQPTLATDMGTMQER | 2265.06 | 2265.077 |
| EVAAFAQFGSDLDAATQQLLSR | 2337.15 | 2337.160 |
The proteins were separated on an SDS/PAGE gel, the band of interest was excised from the gel, and then digested in situ with trypsin. Then 1/20 of the sample was analyzed by matrix-assisted laser desorption ionization-MS. The obtained mass spectrometric peptide map was used to identify the α/β-subunits of ATP synthase in the owl Protein database release 29.6 (30, 31). Analysis of protein sequences of α and β ATP synthase from the Institute of Biology and Chemistry of Proteins showed ≈23% homology and ≈57% similarity.