A novel lectin with potent antitumor, mitogenic and HIV-1 reverse transcriptase inhibitory activities from the edible mushroom Pleurotus citrinopileatus

• Published in: Biochimica et biophysica acta Vol. 1780; no. 1; pp. 51 - 57
• Main Authors: Li, Y.R., Liu, Q.H., Wang, H.X., Ng, T.B.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 2008
• Subjects: Agaricales - chemistry; Amino Acid Sequence; Animals; Antineoplastic Agents - chemistry; Antineoplastic Agents - isolation & purification; Antineoplastic Agents - pharmacology; Antitumor activity; Cell Line, Tumor; Cell Proliferation - drug effects; Chromatography, Gel; Chromatography, Ion Exchange; Electrophoresis, Polyacrylamide Gel; Fruiting Bodies, Fungal - chemistry; Hemagglutinating activity; Hemagglutination Tests; HIV Reverse Transcriptase - antagonists & inhibitors; HIV-1 reverse transcriptase inhibitory activity; Lectin; Lectins - chemistry; Lectins - isolation & purification; Lectins - pharmacology; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Mitogenic activity; Molecular Sequence Data; Molecular Weight; Pleurotus citrinopileatus; Reverse Transcriptase Inhibitors - chemistry; Reverse Transcriptase Inhibitors - isolation & purification; Reverse Transcriptase Inhibitors - pharmacology; Sarcoma, Experimental - pathology; Sarcoma, Experimental - prevention & control; Spleen - cytology; Spleen - drug effects; Hemagglutinating activity; Lectin; Pleurotus citrinopileatus; Antitumor activity; Mitogenic activity; HIV-1 reverse transcriptase inhibitory activity
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2007.09.004

The objective of the present study was to isolate a lectin from fresh fruiting bodies of the mushroom Pleurotus citrinopileatus and examine it for various biological activities. The isolation procedure comprised ion exchange chromatography on DEAE-cellulose, CM-celluloses, and Q-Sepharose, and gel filtration on Superdex 75. A homodimeric 32.4 kDa lectin displaying high hemagglutinating activity was isolated with over 110 fold of purification. Its N-terminal amino acid sequence, QYSQMAQVME, has not been reported for other lectins. The lectin was unadsorbed on DEAE-cellulose in 0.001 M NH 4HCO 3 buffer (pH 9.4), but adsorbed on CM-cellulose in 0.001 M NH 4OAc buffer (pH 4.8) and eluted by approximately 0.05 M NaCl in the same buffer. The lectin was subsequently adsorbed on Q-Sepharose and eluted by a linear gradient of 0–0.2 M NaCl in 10 mM NH 4HCO 3 buffer (pH 8.5). The lectin was obtained in a purified form after gel filtration by fast protein liquid chromatography on Superdex 75. The hemagglutinating activity of the lectin was inhibited by maltose, O-nitrophenyl-β- d-galactopyranoside, O/P-nitrophenyl-β- d-glucuronide and insulin. It was stable at temperatures up to 60 °C, and in NaOH and HCl solutions up to 0.1 M and 0.006 M concentration, respectively. It was sensitive to inhibition by HgCl 2 and potentiation by AlCl 3. The lectin exerted potent antitumor activity in mice bearing sarcoma 180, and caused approximately 80% inhibition of tumor growth when administered intraperitonealy at 5 mg/kg daily for 20 days. It elicited a mitogenic response from murine splenocytes in vitro with the maximal response at a lectin concentration of 2 μM. The lectin inhibited HIV-1 reverse transcriptase with an IC 50 of 0.93 μM. It was devoid of antifungal activity.