Production of leptin in Escherichia coli: A comparison of methods

A procedure is described for gram-scale refolding of Escherichia coil-deriv ed human leptin inclusion bodies. Refolding was achieved by gradually reduc ing denaturant using a diafiltration method. Refolded leptin is characteriz ed by in vivo modulation of food intake, reduction in body weight, and lowe ring of insulin and glucose levels in ob/ob mice. In addition, refolded lep tin is characterized by radioimmunoassay (RIA) and activation of the leptin receptor in a cell-based assay. For comparison we also refolded leptin by a simple dilution method and produced periplasmic derived leptin, which did not require ex vivo folding. Leptin produced by these three methods and le ptin obtained from commercial sources were compared using the RIA and the c ell-based assay and appeared to be of comparable quality and potency. (C) 1 998 Academic Press.