title: Purification and characterization of the lectin from taro (Colocasia esculenta) and its effect on mouse splenocyte proliferation in vitro and in vivo.
abstract: Lectins are proteins found in a wide range of organisms, with the ability to bind reversibly to specific carbohydrates. They can display important biological activities, such as the activation of the cell cycle in lymphocytes. Storage proteins with lectin activity have been reported in tuberous plant species, such as Colocasia esculenta, popularly known as taro. A simple strategy based on Cibacron Blue chromatography was used to purify a 12 kDa polypeptide 1.3-fold, with a recovery of 30 %. The purified protein was identified as tarin by mass spectrometry, which indicated that it was present in G1a/G1d isoforms. Tarin exhibited both agglutinating activity against hamster erythrocytes and mitogenic activity in vitro and in vivo toward mouse splenocytes. Optimum cellular proliferation in vitro was achieved by 625 ng of the crude extract or 500 ng of the purified tarin. Total mouse splenocyte proliferation measured after 5 days of intraperitoneal inoculation of purified tarin was increased 3.3-fold in comparison to the control group. Half of the proliferating cells were identified as B lymphocytes by flow cytometry. These results show that this is an efficient and simple strategy to purify tarin and aid in establishing this protein as a new therapeutic drug, able to promote cell proliferation in a murine model.
authors.affiliation: Instituto de Química, Universidade Federal do Rio de Janeiro (UFRJ), Avenida Athos da Silveira Ramos, 149 Bloco A, sala 545, Cidade Universitária, Rio de Janeiro, RJ, CEP 21941-909, Brazil.
authors.forename: Patrícia Ribeiro
authors.initials: PR
authors.lastname: Pereira
authors.forename: Eduardo Mere
authors.initials: EM
authors.lastname: Del Aguila
authors.forename: Maurício Afonso
authors.initials: MA
authors.lastname: Verícimo
authors.forename: Russolina Benedeta
authors.initials: RB
authors.lastname: Zingali
authors.forename: Vânia Margaret Flosi
authors.initials: VM
authors.lastname: Paschoalin
authors.forename: Joab Trajano
authors.initials: JT
authors.lastname: Silva
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D031060:Colocasia / Q000737:chemistry* / Q000235:genetics; D006224:Cricetinae; D005916:Globulins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D037102:Lectins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D008214:Lymphocytes / Q000187:drug effects; D051379:Mice; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D013154:Spleen / Q000166:cytology / Q000187:drug effects
chemical_list: D005916:Globulins; D037102:Lectins; D010940:Plant Proteins; C094238:TAR1 protein, Colocasia esculenta