Mass spectrometry identification of circulating alpha-1-B glycoprotein, increased in aged female C57BL/6 mice

• Published in: Biochimica et biophysica acta Vol. 1770; no. 1; pp. 79 - 86
• Main Authors: Stehle, John R., Weeks, Mark E., Lin, Kai, Willingham, Mark C., Hicks, Amy M., Timms, John F., Cui, Zheng
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 2007
• Subjects: 2D SDS-PAGE; Aging; Alpha-1-beta glycoprotein; Animals; Electrophoresis, Gel, Two-Dimensional; Female; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mouse; Orosomucoid - metabolism; Peritoneal lavage; Plasma proteins; Protein Processing, Post-Translational; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Aging; Plasma proteins; Mouse; Peritoneal lavage; 2D SDS-PAGE; Alpha-1-beta glycoprotein
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2006.06.020

In this study, we surveyed the profiles of mouse circulating proteins by 2-dimensional SDS-PAGE in different strains, sexes and ages. Among visible protein spots on 2-D gels with silver-staining, we identified a unique set of 7 seemingly-related proteins whose levels were consistently elevated in older C57BL/6 female mice. This set of 7 proteins was absent in C57BL/6 males or in BALB/c mice of either sex of any age. When C57BL/6 female mice were crossed with BALB/c males, the age-related increase of these proteins became sporadic and not linear in the F1 offspring. All 7 spots of this protein group were picked and subjected to identification by mass spectrometric analysis after tryptic digestion. The results showed that all 7 spots were different isoforms of α
1B-glycoprotein with different degrees of post-translational modifications, such as phosphorylation. These results suggest that α
1B-glycoprotein changes in mice in a sex and age dependent manner.