Abstract
We already reported the use of a long synthetic signal peptide (LSSP) to secrete the
Streptomyces
sp. TO1 amylase by
Streptomyces lividans
strain. We herein report the expression and secretion of the rat CD11b A-domain using the same LSSP and
S. lividans
as host strain. We have used the
Escherichia coli/Streptomyces
shuttle vector pIJ699 for the cloning of the A-domain DNA sequence downstream of LSSP and under the control of the constitutive
erm
E-
up
promoter of
Streptomyces erythraeus
. Using this construct and
S. lividans
as a host strain, we achieved the expression of 8 mg/L of soluble secreted recombinant form of the A-domain of the rat leukocyte
β
2 integrin CD11/CD18 alpha M subunit (CD11b). This secreted recombinant CD11b A-domain reacted with a function blocking antibody showing that this protein is properly folded and probably functional. These data support the capability of
Streptomyces
to produce heterologous recombinant proteins as soluble secreted form using the “LSSP” synthetic signal peptide.