Fig. 1

Identification of a processed and secreted form of ob protein in mouse serum

(A) Schematic representation of the precursor (ob 1–167) and mature (ob 22–167) form of mouse ob protein. (B) Amino-terminal sequence of secreted, purified recombinant mouse ob protein from insect cells transfected with a full-length ob expression plasmid. The arrow indicates the cleavage site in the precursor molecule. (C) Immunoblot of sera from normal (wt) and db mice with anti-ob antibody. (D) Immunoblot of lysates from COS-7 cells transfected with mouse ob expression plasmid (COS) and bacte-rially expressed ob protein lacking the first 21 amino acids (Ec) with anti-ob antibody, p, precursor; m, mature forms of ob protein, M, molecular weight standards in kD.