钯配合物对结核杆菌RecA intein蛋白质剪接的抑制作用

Inhibition of Protein Splicing of Mycobacterium tuberculosis RecA intein by Pd Complexes

研究了5种钯配合物Pd(bipy)Cl2,Pd(phen)Cl2,[Pd(dien)Cl]Cl,trans-Pd(NH3)2Cl2和cis-Pd(NH3)2 Cl2对结核杆菌RecA intein蛋白质剪接的抑制作用.结果表明,trans-Pd(NH3)2 Cl2的抑制活性最好,IC50=3.3×10-5 mol/L.钯配合物通过与intein的第一个氨基酸(半胱氨酸)配位,从而抑制蛋白质的剪接活性.荧光猝灭的动力学数据表明,配体的大小会明显影响钯配合物与intein的相互作用,配体越大,作用越慢.

The abilities of five Pd complexes,including Pd（bipy）Cl2,Pd（phen）Cl2,[Pd（dien）Cl]Cl,trans-Pd（NH3）2Cl2 and cis-Pd（NH3）2Cl2,to inhibit protein splicing of Mycobacterium tuberculosis RecA intein have been evaluated.The results showed that trans-Pd（NH3）2Cl2 has the best inhibition efficiency（IC50=3.3×10-5 mol/L）.Competition experiments suggest that the inhibition of protein splicing can be ascribed to the interaction between Pd complexes and the first residue（cysteine） of RecA intein.Furthermore,the difference in the fluorescence quenching of ΔΔIhh-CM by Pd complexes is most likely due to the ligand steric hindrance.