title: A novel lectin with potent antitumor, mitogenic and HIV-1 reverse transcriptase inhibitory activities from the edible mushroom Pleurotus citrinopileatus.
abstract: 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 NH4HCO3 buffer (pH 9.4), but adsorbed on CM-cellulose in 0.001 M NH4OAc 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 NH4HCO3 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-beta-d-galactopyranoside, O/P-nitrophenyl-beta-d-glucuronide and insulin. It was stable at temperatures up to 60 degrees C, and in NaOH and HCl solutions up to 0.1 M and 0.006 M concentration, respectively. It was sensitive to inhibition by HgCl2 and potentiation by AlCl3. 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 microM. The lectin inhibited HIV-1 reverse transcriptase with an IC50 of 0.93 microM. It was devoid of antifungal activity.
authors.affiliation: State Key Laboratory for Agrobiotechnology and Department of Microbiology, China Agricultural University, Beijing 100094, China.
authors.forename: Y R
authors.initials: YR
authors.lastname: Li
authors.forename: Q H
authors.initials: QH
authors.lastname: Liu
authors.forename: H X
authors.initials: HX
authors.lastname: Wang
authors.forename: T B
authors.initials: TB
authors.lastname: Ng
mesh_terms: D000363:Agaricales / Q000737:chemistry*; D000595:Amino Acid Sequence; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D048690:Fruiting Bodies, Fungal / Q000737:chemistry; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors*; D006386:Hemagglutination Tests; D037102:Lectins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D008969:Molecular Sequence Data; D008970:Molecular Weight; D018894:Reverse Transcriptase Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D012513:Sarcoma, Experimental / Q000473:pathology / Q000517:prevention & control*; D013154:Spleen / Q000166:cytology / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D037102:Lectins; D018894:Reverse Transcriptase Inhibitors; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase