Identificação, isolamento e caracterização parcial da lectina de entrecascas de Abarema cochliacarpos (Gomes 1803) Barneby & Grimes 1996

Abstract

Several plants are used by man for therapeutic use and propagated throughout the generations. There is currently a growth in research seeking to identify and isolate active substances present in these organisms in order to create new drugs. The production of the active principles of these organisms is related to their defense mechanism against external agents. These substances are normally classified into primary and secondary metabolites. Lectins are primary metabolism proteins that can assume several biological roles, including antibacterial, antifungal, anti-inflammatory, anti-tumor and healing activities. These activities are related to the ability that lectins have to bind to carbohydrates present on the cell surface of target organisms, preventing their development and / or inducing a cellular response. Abarema cochliacarpos (Gomes) Barneby & Grimes, popularly known as barbatimão, is a plant used in folk medicine to treat ulcers, wounds, skin infections, gastritis, among others. This study aims to investigate the presence of lectin in A. cochliacarpos bark and perform its partial purification and characterization. The extract was prepared and filtered over activated carbon in an attempt to remove compounds that are not of interest. An aliquot of this filtrate was applied to a chitin chromatographic column and the proteins of interest were eluted with 1 M acetic acid. Then, the sample was dialyzed to remove the elution solution and its hemagglutinating activity was evaluated (512). From then on it was called AcBL (A. cochliacarpos bark lectin). It was not possible to confirm the purification of lectin using SDS-PAGE electrophoresis in reducing and non-reducing conditions; the gel showed the presence of two protein bands in both conditions. The measurement of proteins and phenols was carried out at all stages of purification, as well as characterization tests. AcBL was inhibited by casein, showed thermostability over a wide temperature range, demonstrated to be a protein with an acid-neutral character and had its activity reduced in the presence of EDTA, calcium and magnesium ions. The development of this work contributes to the isolation of new proteins, presenting regional relevance when investigating lectins from a medicinal plant in Northeast Brazil, which may represent a new biomaterial with high biotechnological potential.