Palm L, Burka L T, Højrup P, Stevens R D, Tomer K B
NIEHS, Research Triangle Park, NC 27709, USA.
Int J Biochem Cell Biol. 1996 Dec;28(12):1319-26. doi: 10.1016/s1357-2725(96)00090-8.
The aim of the work is to identify and characterize the hemoglobins found in B6C3F1 mice using mass spectrometry. The primary structures are compared to those reported for BALB/c mice. Individual hemoglobin chains were isolated by reverse-phase high performance liquid chromatography (RP-HPLC). The molecular masses of the globins were determined using electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI). The purified globin chains were enzymatically cleaved and the resulting peptides were separated by RP-HPLC. The chains were identified by N-terminal sequencing and mass spectrometry (MALDI). Selected peptides were analysed by Edman degradation. ESI analysis indicates that B6C3F1 mice have two alpha-globin chains (alpha-1 and alpha-2) and at least three beta-globin chains, beta-1, beta-2 and beta-3. This is one additional alpha- and one additional beta-globin chain than reported in the literature for BALB/c mice. Mass and sequence analysis of enzymatically generated peptides showed variations in the amino acid sequence in the alpha-1, alpha-2, beta-2 and beta-3 chains compared to the BALB/c mouse hemoglobins (alpha, beta (minor) and beta (major)). The study showed that mass spectrometry in combination with traditional protein chemistry is able to identify and locate minor protein sequence variations.
