Targeting transforming growth factor-βreceptor Ⅱ aptamer binding sites prediction and validation studies / 重庆医学

ABSTRACT

Objective To predict the binding sites of transforming growth factor-βreceptor Ⅱ (TβRⅡ ) ectodomain and the aptamer S58 specifically targeted TβRⅡ ,and to confirm the structure stability of the aptamer S 58 in vitro .Methods We created three-dimensional structure by utilizing ssDNA aptamer sequences ,the crystal structure of the TβRⅡ was searched by protein data bank database .According to the results of the molecular docking experiments on aptamer S 58 and TβRⅡ ectodomain ,we sheared the aptamer sequences ,then verified its affinity respectively by biosensor technology and Western blot .Results Binding sites of aptamers S58 and TRβⅡ ectodomain included site Ⅰ(T4 ,T5 ,G6 ,C7) ,site Ⅱ(G13 ,A14 ,T15 ,C16 ,G17 ,C18 ) ,site Ⅲ (T31 ,G32 , T33 ,C34) and site Ⅳ(G40 ,A41 ,T42 ,T43 ,T44 ,G45 ,G46) .We validated the high affinity between aptamer S58 and TRβⅡ ectodo-main .The expression of α-smooth muscle actin(α-SMA) protein in the human tenon′s capsule fibroblasts was descended obviously after the experiment of the aptamer S58 in comparing with the control of DMEM (P< 0 .05) .But the new ssDNA by shear the aptamer ssDNA S58 according to the results were poor than aptamers S58 .Conclusion The aptamer S58 targeted TβRⅡ was high-ly specific with a certain stability ,any changing of structure will reduce the affinity of TβRⅡ .Computer-aided molecular docking technology has become an important means of an exploratory intermolecular interaction ,and can provides a good theoretical basis on medical research .