FIG 3.

LST secreted from P. pastoris is aberrantly glycosylated. (A) LST from P. pastoris culture supernatants migrates as a doublet (left), and treatment with PNGase F eliminates the higher-molecular-mass upper band (right). Lanes: M, protein marker (top to bottom, 250, 150, 100, 75, 50, 37, 25, and 20 kDa); 1, 10 μl of supernatant of flask culture; 2, 10 μl of supernatant of bioreactor culture. (B) Glycosylated and unglycosylated LST cannot be separated during cation exchange chromatography. Lanes: M, protein marker (top to bottom, 250, 150, 100, 75, 50, 37, 25, and 20 kDa); 1 to 6, different fractions collected from a single peak during chromatographic purification.