The plasmid pALCA1SIFN containing cDNA that encodes the human interferon
a-2b was obtained from the ATCC(no. 531667). In this system the expression of the
gene is under the control of an alcA promoter. alcA p is a specific promoter for
expression of different genes in Aspergillusfilamentous. In this plasmid the coding
region of IFN?-2b is preceded by the coding region of a synthetic signal peptide. For
direct expression of the IFNa-2b gene under the control of a T7/lac promotor of
pET24d(+) expression vector, three subcloning steps were carried out which resulted
in the construction of 3 new plamids. pHA1, pHA2 and pHA4 in which the IFNa-2
gene is under the control of lacp, lacuv5p and T7 promoter, respectively. Another
plasrnid, pHA3, was also constiucted and is a modified version of pET24d(+).
Provided there is a synthetic signal peptide preceding the coding region of IFNa2
gene, the protein can be seen in either system, as shown by western blotting, albeit
with a different level of expression. The best product can be seen in the pHA4plasmid
with a T7 pas judged by dot and western blotting