IDENTIFICATION OF 5 HEMOGLOBINS IN B6C3F1 MICE BY MASS-SPECTROMETRY AND SEQUENCE-ANALYSIS

The aim of the work is to identify and characterize the hemoglobins fo und in B6C3F1 mice using mass spectrometry. The primary structures are compared to those reported for BALB/c mice. Individual hemoglobin cha ins were isolated by reversed-phase high performance liquid chromatogr aphy (RP-HPLC). The molecular masses of the globins were determined us ing electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI). The purified globin chains mere enzymatically cle aved 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 i ndicates that B6C3F1 mice have two alpha-globin chains (alpha-1 and al pha-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 ana lysis of enzymatically generated peptides showed variations in the ami no acid sequence in the alpha-1, alpha-2, beta-2 and beta-3 chains com pared to the BALB/c mouse hemoglobins (alpha, beta(minor) and beta(maj or)). The study showed that mass spectrometry in combination with trad itional protein chemistry is able to identify and locate minor protein sequence variations. Copyright (C) 1996 Elsevier Science Ltd