[The expression of pulmonary surfactant proteins B and surfactant protein C in E. coli]

To express biological active surfactant protein B(SP-B) and surfactant protein C(SP-C) combined with synthetic phospholipids to make an ideal exogenous pulmonary surfactant (PS) for the treatment of respiratory distress syndrome (RDS) in future.

Prokaryote expression vector pIN-II-ompA2-B-C was established with the cDNA fragments of mature human SP-B and SP-C, then the fusion protein of mature SP-B with SP-C was expressed in E. coli BL21 induced by IPTG. The expression of fusion protein in E. coli was confirmed by Western blot anlaysis. The biological activity of the expressed product was measured by Wilhelmy's surface balance (MTP-2).

The fusion protein of SP-B with SP-C could be expressed in E. coli BL21, and their molecular weight (Mr) was 20000 on gel electrophoresis, but the amount was small. According to the measurement of Wilhelmy's surface balance (MTP-2), the minimal surface tension of expressed protein in E. coli BL21 could be reduced to 0.004 N/m2 and the area of hysteresis loop was relatively large.

The results of the investigation will be a basis to obtain SP-B and SP-C with gene engineering technology and to create a new way for producing ideal exogenous PS.