Purification and characterization of a heterodimeric mycelial lectin from Penicillium proteolyticum with potent mitogenic activity.

ABSTRACT

In the present study, Penicillium proteolyticum lectin was purified by DEAE-Sepharose chromatography followed by Sephadex G-100 gel filtration chromatography. A sequence of ion-exchange and gel filtration chromatography resulted in 52.30 fold purified lectin with a high yield of 84.21%. The purified P. proteolyticum lectin is a glycoprotein with 2.83% linked carbohydrates. A single band in Native-PAGE, whereas two bands (25.1 kDa and 22.9 kDa) in SDS-PAGE confirmed the heterodimeric nature of the purified lectin. The apparent molecular weight (48 kDa) of P. proteolyticum lectin was further confirmed by gel filtration analysis. Heterodimeric P. proteolyticum lectin was stable within a pH range of 6.5-7.5 and upto a temperature of 30 °C. The lectin activity was strongly inhibited by complex glycoproteins and denaturants. Metal ions are not required for agglutination activity of purified lectin. The lectin showed significant mitogenic response towards mice splenocytes. It exhibited highest mitogenic activity at a concentration of 50 µg/mL. This is a first report on characteristics of purified P. proteolyticum lectin having potent mitogenic potential.