Purification and Characterization of a Mannose-binding Lectin from the Rhizomes of Aspidistra elatior Blume with Antiproliferative Activity  

作　　者：Xiaochao XU Chuanfang WU Chao LIU Yongting LUO Jian LI Xinping ZHAO Els Van DAMME Jinku BAO 

机构地区：[1]College of Life Sciences, Sichuan University, Chengdu 610064, China [2]Leshan Teachers' College, Leshan 614000, China [3]Department of Molecular Biotechnology, Ghent University, 9000 Gent, Belgium

出　　处：《Acta Biochimica et Biophysica Sinica》2007年第7期507-519,共13页生物化学与生物物理学报（英文版）

基　　金：This work was supported by the grants from the National Natural Science Foundation of China （30000032 and 30270331）, the Science and Technology Fund for Distinguished Young Scholars of Sichuan Province （06ZQ026-035）, the Key Technologies R＆D Program of Sichuan Province （2006Z08-010） and European Commission （EMPR0） and the Centers of Excellence of the K. U. Leuven （EF/05/15）

摘　　要：A lectin with a novel N-terminal amino acid sequence was purified from the rhizomes of Aspidistra elatior Blume by ammonium sulphate precipitation, ion exchange chromatography on diethylaminoethyl-Sepharose and carboxymethyl-Sepharose and gel filtration chromatography on Sephacryl S-100. The A. elatior Blume lectin （AEL） is a heterotetramer with a molecular mass of 56 kDa and composed of two homodimers consisting of two different polypeptides of 13.5 kDa and 14.5 kDa held together by noncovalent interactions. Hapten inhibition assay indicated that hemagglutinating activity of AEL towards rabbit erythrocytes could be inhibited by D-mannose, mannan, thyroglobulin and ovomucoid. The lectin was stable up to 70 ℃ , and showed maximum activity in a narrow pH range of 7.0-8.0. Chemical modification and spectrum analysis indicated that tryptophan, arginine, cysteine and carboxyl group residues were essential for its hemagglutinating activity. However, they might not be present in the active center, except some carboxyl group residues. AEL also showed significant in vitro antiproliferative activity towards Bre-04 （66%）, Lu-04 （60%） and HepG2 （56%） of human cancer cell lines.A lectin with a novel N-terminal amino acid sequence was purified from the rhizomes of Aspidistra elatior Blume by ammonium sulphate precipitation, ion exchange chromatography on diethylaminoethyl-Sepharose and carboxymethyl-Sepharose and gel filtration chromatography on Sephacryl S-100. The A. elatior Blume lectin （AEL） is a heterotetramer with a molecular mass of 56 kDa and composed of two homodimers consisting of two different polypeptides of 13.5 kDa and 14.5 kDa held together by noncovalent interactions. Hapten inhibition assay indicated that hemagglutinating activity of AEL towards rabbit erythrocytes could be inhibited by D-mannose, mannan, thyroglobulin and ovomucoid. The lectin was stable up to 70 ℃ , and showed maximum activity in a narrow pH range of 7.0-8.0. Chemical modification and spectrum analysis indicated that tryptophan, arginine, cysteine and carboxyl group residues were essential for its hemagglutinating activity. However, they might not be present in the active center, except some carboxyl group residues. AEL also showed significant in vitro antiproliferative activity towards Bre-04 （66%）, Lu-04 （60%） and HepG2 （56%） of human cancer cell lines.

关 键 词：antiproliferative activity Aspidistra elatior Blume chemical modification hemagglutinating activity mannose-binding lectin 

分 类 号：Q5[生物学—生物化学]