Expression and purification of a synthetic human obese gene product

Abstract

Human obese (hOB) protein was recently identified as a secreted hormone-like factor that is exclusively produced by adipose tissue and appears to regulate the size of the body's fat stores. We describe a rapid and efficient repetitive extension PCR method for the construction of a 453-bp synthetic hOB gene with high-frequency codons to optimize expression in Escherichia coli. The use of a bacterial signal sequence fused to hOB together with expression of bacteriocin release protein resulted in efficient release of hOB into the culture medium. The protein was readily purified to homogeneity from the culture medium using a two-step procedure.