Binding of B Cell - Derived Autocrine Growth Factor to Hemoglobin.
- Author:
Jae Seung PARK
;
Il Whan CHOI
;
Young Mi SHIN
- Publication Type:Original Article
- Keywords:
Staphylococcus aureus Cowan I;
Autocrine B cell growth Factpr;
Hemoglobin
- MeSH:
Amino Acid Sequence;
B-Lymphocytes;
Blotting, Western;
Centrifugation;
Chromatography, Ion Exchange;
Chromatography, Liquid;
Electrophoresis, Polyacrylamide Gel;
Humans;
Silver;
Staphylococcus aureus
- From:Korean Journal of Immunology
1998;20(1):25-30
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
Normal human B cells produce autocrine growth factor in response to Staphylococcus aureus Cowan I strain (SAC). However, the functional role and molecular nature of the B cell derived-B cell growth factor (B-BCGF) are largely unknown. We have tried to investigate the nature of B-BCGF using mAb for several years. We report here that B- BCGF is capable of binding to hemoglobin (Hb). The concentrated culture supernatant from tonsillar B cells stimulated with SAC for 24 h was loaded into the fast protein liquid chromatography and ion-exchange chromatography. The peak with BCGF activity was shown to have a M.W. of 16-18 Kda in polyacrylamide gel electrophoresis followed by silver stain. Amino acid sequence of the fraction was found to identical to human hemoglobin (Hb) by more than 85%. However, Hb itself had no BCGF activity. The presence of Hb in culture supernatant was due to the contamination of SRBC during B cell purification. SRSC were completely removed from B cells by percoll-gradient centrifugation and B cells were stimulated with SAC and exogenous Hb was added to the cultures. The Hb fraction from FPLC again showed a BCGF activity. These data strongly suggested that BCGF binds to Hb. We confirmed this in dot blot as well as Western blot. The M.W of Hb-binding BCGF was 20 Kda. This information may provide a rapid progress in research of BCGF.
