Page 7 - BM 2010 Vol.1 No.2

Bioscience Methods
BM 2010, Vol.1, No.2 http://bm.sophiapublisher.com
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Figure 4 Effect of different IPTG concentrations and temperatures on the expression of fusion protein
Note: M: Protein Marker; A: induced by IPTG under 20℃ for 1 h; B: Induced by IPTG under 28℃ for 1 h; C: Induced by IPTG
under 37℃ for 1 h; 1~3: IPTG concentration are 0.1 mmol/L, 0.5 mmol/L, 1 mmol/L, respectively; Arrow indicates the fusion
proteins
Figure 5 The large scale expression of Cry1Ac22 inclusion
Note: M: Protein Marker; 1~4: Induced by 1 mmol/L IPTG
under the IPTG induction for 1 h, 3 h, 6 h, 12 h at 28 ; Arrow℃
indicates the fusion proteins
Figure 6 The fusion protein expression of different transfor-
mants induced by 1 mmol/L IPTG for 12 h at 28℃
Note: 1~6: Different transformants; Arrow indicates the fusion
proteins
Figure 7 Batch purification of the fusion protein
Note: M: Protein marker; 1: Crude cell lysate; 2: The
flow-through of crude cell lysate; 3: 8 mol/L urea wash; 4~7:
The first, second, third and forth elutes after elution with 8
mol/L urea elution buffer D (pH 5.9); Arrow indicates the
purified 6хHis-Cry1Ac22 fusion proteins
Inclusion body is the major form of foreign protein
expressed in the bacteria, whose protein agglutinates
in the host cell to develop active granules in sizes of
0.5~1 micron (μ). Inclusion body is insoluble in water
while easy dissolved in some denaturants such as urea
and hydrochloric acid (Haacke et al., 2008). The
formation of inclusion badies will facilitate the high
expression of foreign protein and prevent protein
degradation by proteinase as well as avoiding
poisoning the host cell from foreign protein (Hao et al.,
1996).
In the present research, Cry1Ac22 fusion protein