Purificação, caracterização físico-química e biológica de SLA: uma nova lectina extraída de sementes de Swartzia laevicarpa Amshoff

Abstract

Lectins are proteins of non-immune origin that have at least one specific and reversible carbohydrate binding domain without enzymatic action. These proteins are widely distributed in nature. Lectins isolated from legume seeds are among the most studied, have homology and are important markers of evolution within this plant family. There is little information about the lectins of the basal tribes of the subfamily Papilionoideae and new information is important to solidify your knowledge of the lectins of these tribes. This study aimed to purify a new lectin from Swartzia laevicarpa, to characterize its physical-chemical and mass spectrometry proprieties and test as its ability to cause inflammation and pain and their toxicity against Artemia sp. The lectin was purified by ammonium sulfate fractionation followed by ion exchange chromatography and molecular exclusion. Named SLA, the lectin shows the electrophoretic profile of a chain of 30 kDa and, unlike SLL presents subunits around 13 and 17 kDa. Has affinity for GalNAc and Gal derivatives, and presents thermodynamic binds characteristics of different for Gal and GalNAc. SLA caused inflammation in a model of paw edema of mice and hypernociception linked to inflammation. SLA also showed toxicity against stage II nauplii of Artemia sp. The lectin isolated and characterized in this work proves to be an interesting tool and corroborate the taxonomic placement of Swartzeae. SLA also demonstrate the biotechnological potential in the study of models from inflammation and pain. By mass spectrometry we found that SLA has at least two isoforms and provides glycoforms. It has approximately 250 amino acid residues and in this work were determined 179 of them. SLA showed similarity with lectins from other basal tribes as VML and SJA, corroborating the classification as Swartzieae Papilionoideae tribe and demonstrating the use of lectins as a taxonomic tool.