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Lectins are ubiquitous proteins in nature, with non-immune origin, which have at least one non-catalytic domain that binds carbohydrates specifically and reversibly. They can be found in vegetables leaves, stems and seeds. The Dalbergieae tribe has lectins which have specificity for different carbohydrates and also have several biological activities such as induction of rat paw edema, release of chemotactic mediators by macrophages, vasorelaxant effect in rat aortas, among others. This study aimed to isolate, purify and physiochemically characterize a lectin found in seeds of Andira pisonis Mart (Dalbergieae). Andira pisonis Mart seeds were ground into a fine powder and subjected to total protein extraction in 1 M ammonium sulfate. Soluble proteins were subjected to hemagglutination activity quantification by the Bradford method and essays of hemagglutination inibition activity by sugar. The lectin from Andira pisonis Mart (APL) was purified by affinity chromatography on Sepharose- Mannose matrix eluted in 0.1 M glycine buffer pH 2.6 with 0.15 M NaCl. The eluted fraction was dialyzed against distilled water, lyophilized and subjected to ion exchange chromatography on HiTrap SP XL 01. APL was eluted on 20 mM sodium acetate buffer pH 4.5 gradient of 0-1M NaCl. APL hemagglutinated rabbit erythrocytes (enzymatically treated) and other lectins from the tribe Dalbergieae and showed specificity for mannose (25 mM). SDS-PAGE analysis showed that APL is composed of a major 34 kDa double band and a minor 8 and 9 kDa double band. APL showed thermostability at 60° C. Further studies are still needed in order to better physicochemically characterize this protein and study its biotechnological potential on the referred conditions of vasorelaxant effect and chemotatic mediator.

Lectins are (glycol) proteins that bind specifically and reversibly to carbohydrates. These proteins, in particular those from plant, are important tools in glycobiochemistry and glycobiology. Canavalia bonariensis Lindl is a species of Leguminosae family, Papilionoideae subfamily, tribe Phaseoleae, subtribe Diocleinae, native of the southern region of the country. The objective of this work was to purify a lectin from C. bonariensis (CaBo) seeds through affinity chromatographic. The process of purification of CaBo (Canavalia bonariensis Lectin) was monitored by SDS-PAGE and hemagglutinating activity and showed that the purified lectin is characterized by an electrophoretic profile consists of a higher band with approximately 26 kDa, and two bottom bands with apparent molecular mass of 14 and 12 kDa. The analysis by mass spectrometry indicated that CaBo has a chain with molecular mass of 25,512 kDa and and two subunits (β and γ chains) with molecular mass of 12,999 Da and 12,537 Da, respectively. CaBo also had its primary sequence partially determined by tandem mass spectrometry, obtaining 61% of the total sequence of the protein. CaBo was tested for the thermostability of their hemagglutinating activity after incubation for one hour at different temperatures (40° to 80° C), losing activity only at 80° C after one hour. Regarding its stability at different pH (4.0 to 10.0), CaBo was stable in a pH range between 7.0 and 9.0. The CaBo activity was also affected after serial dilution in the presence of the chelating agent EDTA and it was recovered significantly after addition of CaCl2 and MnCl2 0,005 mol/L, proving to be dependent of divalent metal cations.

Andira anthelmia seeds, a species belonging to the Leguminosae family, Papilionoideae subfamily, Dalbergieae tribe, have a glucose/mannose specific lectin that agglutinates rabbit erythrocytes treated with trypsin. The Dalbergieae tribe has lectins which have specificity for different carbohydrates including mannose and also have several biological activities such as induction of rat paw edema, release of chemotactic mediators by macrophages, vasorelaxant effect in rat aortas, termiticide activity, potential fungicide action, among others. This study aimed to isolate, purify and physicochemically characterize a lectin found in seeds of Andira anthelmia. The lectin from Andira anthelmia seeds was purified by affinity chromatography on Mannose-Sepharose matrix followed by ion exchange chromatography on DEAE-Sephacel matrix. This procedure resulted in a purified lectin, named AAL. AAL purification process was monitored by specific hemagglutinating activity and SDS-PAGE, in which it was observed that this lectin has a molecular weight of approximately 20 kDa and four others subunits of approximately 15 and 14 kDa. This lectin is a glycoprotein with approximately 1.89% of carbohydrates on its composition and shows high stability, being able to maintain their hemagglutinating activity in a wide pH range and after exposure to temperatures of 70 °C for one hour. After dialysis against the chelating agent EDTA, AAL lost its hemagglutinating activity, but recovered its action after the addition of metals, being, therefore, dependent on divalent metal cations. In this study a new lectin from Dalbergieae was purified and characterized. Further analyzes are needed in order to best evaluate their biotechnological applications.