Institution: | a NIEHS, P.O. Box 12233, Research Triangle Park, NC 27709, U.S.A. b Odense University, Department of Molecular Biology, Campusvej 55, 5230, Odense M, Denmark c Duke Medical Center, Mass Spectrometry Facility, P.O. Box 14991, Research Triangle Park, NC 27709, U.S.A. |
Abstract: | 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 reversed-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 -globin chains ( -1 and -2) and at least three β-globin chains, β-1, β-2 and β-3. This is one additional - and one additional β-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 -1, -2, β-2 and β-3 chains compared to the BALB/c mouse hemoglobins ( , βminor and βmajor). The study showed that mass spectrometry in combination with traditional protein chemistry is able to identify and locate minor protein sequence variations. |