Clematis montana lectin, a novel mannose-binding lectin from traditional Chinese medicine with antiviral and apoptosis-inducing activities.
A novel mannose-binding lectin (designated CML) was isolated from Clematis montana Buch.-Ham stem (Ranunculaceae) using ion exchange and gel filtration chromatographies on DEAE-Sepharose and Sephacryl S-100. The purified C. montana lectin was a homodimer of 11,968.9 Da subunits as determined by gel filtration and MS. The hemagglutinating activity of CML was inhibited by branched oligomannosides. The N-terminal 15-amino acid sequence of CML, DNVKYSGQVKNTGSA, has not been reported for other lectins. Also, the peptide mass fingerprinting assay confirmed that there is no match result of similar plant lectins for CML, indicating CML may be a novel plant lectin. CML showed marked antiviral activity against various viruses in cell culture. Subsequently, CML was also found to exhibit remarkable inhibitory effect on L929, HeLa, MCF7 and HepG2 cells. Furthermore, CML specially induced L929 cell apoptosis in dose-dependent manner as evidenced by MTT, fluorescent microscopy, LDH activity-based cytotoxicity assays and DNA ladder. Moreover, due to both caspase inhibitors and Western blot analyses, caspase was also found to play the important role in the potential apoptotic mechanism of CML. When the carbohydrate-binding site was fully inhibited by sugars, cytotoxicity was abruptly decreased and apoptotic phenomenon in L929 cells was not observed, suggesting a significant correlation between mannose-binding-specific activity and the antineoplastic mechanism.
Peng
Hao
H
School of Life Sciences, State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610064, China.
Lv
Hui
H
Wang
Ying
Y
Liu
Yan-hong
YH
Li
Chun-yang
CY
Meng
Liang
L
Chen
Fang
F
Bao
Jin-ku
JK
D000595:Amino Acid Sequence; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D000998:Antiviral Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D045744:Cell Line, Tumor / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape; D039324:Clematis / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000378:metabolism; D006801:Humans; D037601:Mannose-Binding Lectin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D008516:Medicine, Chinese Traditional; D008969:Molecular Sequence Data; D037121:Plant Lectins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D014780:Viruses / Q000187:drug effects
D000970:Antineoplastic Agents; D000998:Antiviral Agents; D004791:Enzyme Inhibitors; D037601:Mannose-Binding Lectin; D037121:Plant Lectins; D053148:Caspase 3; D053181:Caspase 8