Barroso-Neto Ito L, Delatorre Plinio, Teixeira Claudener S, Correia Jorge L A, Cajazeiras João B, Pereira Ronniery I, Nascimento Kyria S, Laranjeira Eva P P, Pires Alana F, Assreuy Ana M S, Rocha Bruno A M, Cavada Benildo S
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
Departamento de Biologia Molecular, Universidade Federal da Paraíba, João Pessoa, PB, Brazil.
Int J Biol Macromol. 2016 Jan;82:464-70. doi: 10.1016/j.ijbiomac.2015.10.052. Epub 2015 Oct 21.
Lectins are proteins that show a variety of biological activities. However, they share in common at least one domain capable of recognizing specific carbohydrates reversibly without changing its structure. The legume lectins family is the most studied family of plant lectins, in particular the Diocleinae subtribe, which possesses high degree of structural similarity, but variable biological activities. This variability lies in small differences that can be analyzed in studies based on structures. In particular, Dioclea sclerocarpa seed lectin (DSL) presents low ability to relax endothelialized rat aorta in comparison with other Dioclea lectins such as Dioclea violacea (DVL), Dioclea virgata (DvirL) and Dioclea rostrata (DRL). The DSL relaxation mechanism relies on nitric oxide production and carbohydrate recognition domain (CRD). This feature can be explained by structural differences, since DSL has a carbohydrate recognition domain design less favorable. In addition, the presence of a glutamate residue at position 205 proved to be a decisive factor for the low relaxant effect of Dioclea lectins.
凝集素是一类具有多种生物学活性的蛋白质。然而，它们至少有一个共同的结构域，能够在不改变自身结构的情况下可逆地识别特定碳水化合物。豆科凝集素家族是研究最多的植物凝集素家族，特别是蝶豆亚族，其具有高度的结构相似性，但生物学活性各不相同。这种变异性源于一些微小差异，这些差异可以在基于结构的研究中进行分析。特别是，与其他蝶豆凝集素如紫花蝶豆凝集素（DVL）、长梗蝶豆凝集素（DvirL）和喙蝶豆凝集素（DRL）相比，硬果蝶豆种子凝集素（DSL）舒张内皮化大鼠主动脉的能力较低。DSL的舒张机制依赖于一氧化氮的产生和碳水化合物识别结构域（CRD）。这一特性可以通过结构差异来解释，因为DSL的碳水化合物识别结构域设计不太有利。此外，第205位谷氨酸残基的存在被证明是蝶豆凝集素舒张作用较弱的决定性因素。
