In silico identification of new potentially active brassinosteroid analogues

Brassinosteroids (BRs) are hormones found in a wide range of plant species, they are synthesized at low concentrations and are essential for normal growth and development. These phytohormones are recognized by the Leucine-rich-repeat ectodomain of the receptor-like-kinase BRI1 which leads to subsequent downstream signaling mediating plant growth/development. In spite of the advantages that BRs offer, their extraction from natural sources is highly expensive, which constitutes one of its major limitations. Thus, the design and synthesis of structural and/or functional analogues of BRs with higher activity and lower cost has a great practical significance in world agriculture. In this matter, in silico methods, such as molecular docking, are valuable tools for the prediction and design of new compounds with improved activity. In this work we performed molecular docking simulations of 20 synthetic steroids in order to identify active compounds. Contact based analysis, level of exposure of polar groups to the solvent and binding affinity were the parameters used to consider if a synthetic steroid was active. Our results suggested that 17 out of a total of 20 of the analyzed steroids can potentially activate BRI1 receptor.