Recombinant ob-gene product reduces food intake in fasted mice

The ob-gene encodes for a protein of 167 amino acids which is expressed exclusively in white adipose tissue. The ob-gene product is probably released from adipocytes as a soluble hormone of 146 amino acids and has been proposed as a satiety factor. To test this hypothesis, the soluble portion of the ob-gene product devoid of signal sequence was expressed in E. coli and purified. The purified protein, which contains two Cys residues, was recovered from the periplasm in an oxidized form. After a single intravenous injection, the ob-gene product decreased food intake after fasting in normal mice. The results show that recombinant ob-gene product can be obtained in a functionally active conformation and provide direct proof that this protein is a satiety factor.