ISSN:
1574-695X
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Biologie
,
Medizin
Notizen:
Previously, we reported a plasmid-bearing Salmonella typhimurium strain capable of secreting human interleukin-6 (hIL-6) when genetically fused to the Escherichia coli hemolysin transport signal (HlyAS). Stationary phase culture supernatants of this strain revealed three major forms of hIL-6-HlyAS fusion protein (apparent molecular masses 32.4, 30.3, 27.0 kDa), at which the largest protein presumably represented full-length hIL-6-HlyAS. The biological activity of the hIL-6-HlyAS protein mixture was similar to that of mature hIL-6. Accumulation of hIL-6-HlyAS in the culture supernatant occurred only during the initial growth phase, whereas in stationary phase and under in vitro conditions successive cleavage into the two truncated forms was observed. On the other hand, in whole cell lysates only full-length hIL-6-HlyAS could be detected, accounting for more than 50% of the totally synthesized protein. Upon cell fractionation, cellular hIL-6-HlyAS was exclusively found in the membrane fraction. These results suggest, that in S. typhimurium production and secretion of hIL-6-HlyAS is restricted to growing cells. A specific processing by a Salmonella-derived protease did not affect the biological activity of the fusion protein.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1574-695X.2000.tb01447.x
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