I have a problem about protein solubility (inclusion body). The information of gene construct is as follows;
i) pQE-80L system (N-terminal His-tag)
ii) gene size, 1.5 kb (signal peptide removed)
iii) fully sequenced (no error)
iv) over-expressed by adding IPTG (0.001-1 mM)
v) 18, 25, and 37 degree incubation tested
vi) host cell, BL21 (DE3)
BUT all over-expressed protein is localized in insoluble fraction by all trials I couldn't detect enzyme activity from soluble fraction. To be strange, when I inoculated the cell on LB plate containing fluorescent substrate, it definitely showed fluorescence around the cell.
how can I figure it out? what's the problem?
Edited by todd, 21 February 2005 - 09:50 AM.