Elucidation of the primary structure and molecular modeling of Parkia pendula lectin and in vitro evaluation of the leishmanicidal activity

Structure-function study of plant lectins has received attention for elucidating possible mechanisms of lectins in cell models. Lectins have the ability to interact with target glycans and trigger responses able to inhibit the development of various pathogens. In this work, we report amino acid sequencing, prediction of the threedimensional structure of P. pendula lectin (PpeL) and the effect of this lectin on inhibiting the development of Leishmania infantum promastigote. PpeL was purified on affinity chromatography and has haemagglutinating activity after exposure to temperatures up to 50 C and at a pH corresponding to the range of 5.0 and 7.0. PpeL consists of 447 amino acids; the theoretical average molecular mass was 47,410 Da. The three-dimensional model of PpeL revealed that it consists of three 8-prism domains tandemly arranged with each one presenting a different carbohydrate recognition domain (CRD). PpeL inhibited growth of L. infantum promastigotes (45.6 +/- 1.92 %) within 48 h, an effect that occurred via the CRD, suggesting an interaction between PpeL and glycans from L. infantum. Our results confirm the leishmanicidal potential of PpeL, suggesting that this lectin may be a new strategy for the development of antileishmanial drugs.