Purificação de lectina presente nas sementes de Dioclea megacarpa Rolfe

Abstract

Lectins, characterized by their ability to reversibly bind to carbohydrates, are a group of protein molecules widely distributed in the five kingdoms of life, with lectins belonging to the Plantae kingdom being the most described and studied, and the Leguminosae family constituting the largest number of taxa studied. The genus Dioclea, belonging to this family, is one of the most cited groups regarding the presence of lectins, with considerable reports in the literature of potential applications in biomedicine, including antimicrobial and antitumor activities, for example. The species Dioclea megacarpa is a native plant, predominantly from the northern and northeastern Brazilian states, as well as Central American countries. Based on existing protocols on the purification of Diocleinae lectins, this study adopted such techniques for purifying a lectin from Dioclea megacarpa seeds. The established protocol involved obtaining fine flour from the seeds through grinding in a coffee mill, followed by extraction of total proteins in a 0.15M NaCl solution. After obtaining the protein extract, affinity chromatography was performed on a Sephadex G-50 matrix to purify the lectin present in the extract. The progress and efficiency of the purification protocol was evaluated through hemagglutinating activity and protein quantification assays, determining the effectiveness of carrying out affinity chromatography in lectin purification, obtaining a sample almost 9 times more purified than the total protein extract, establishing thus, procedures to be used during new studies involving lectins of this species.