3A分辨率绿豆胰蛋白酶抑制剂Lys活力碎片—牛胰蛋白酶(MBILF-BTRY)复合物的晶体结构分析和分子模型

用分子置换法成功地解得了MBILF-BTRY的晶体结构,并得到了它的立体结构模型。绿豆胰蛋白酶抑制剂属于絲氨酸蛋白酶抑制剂中结构最复杂的Bowman-Birk型抑制剂。这一类型抑制剂的立体结构以前尚未见报道。MBILF-BTRY复合物晶体的晶胞参数为a=62.99,b=63.54,c=69.70,α=β=γ=90°,空间群为P2_12_12_1,复合物分子量约为27500daltons。用理学电机的Ru-300型转靶X光机及AFC-5型四园衍射仪收集了分辨率为3范围内的独立衍射点5142个。以蛋白质数据库所取得的牛胰蛋白酶分子的座标为     

A MOLECULAR ORBITAL STUDY ON ADENOSINE PHOSPHATES

AMP, ADP and ATP are calculated using the CNDO method, and ATP is studied by an ab initio calculation.The essential features of the electronic structure of these molecules are described in detail. Their ionization potentials, dipole moments and bond orders are given.The interaction between ATP with metal ions and enzyme molecules is discussed.     

0.3 nm分辨率绿豆胰蛋白酶抑制剂Lys活力碎片—牛胰蛋白酶(MBILF-BTRY)复合物的晶体结构分析和分子模型

Crystal structure of MBILF-BTRY complex was successfully solved by molecular replacement method and its 3-dimensional molecular model was thereby derived. Mung bean trypsin inhibitor belongs to Bowman-Birk inhibitor group, which is by far the most complicated among the ten fundamental groups of serine protease inhibitor. Neither the 3-dimensional structure of Bowman-Birk inhibitor group nor the stereoscopic conformation of its complex with protease has ever been reported. The crystallographic data of MBILF-BTRY complex are found to be a=....     

CRYSTAL STRUCTURE DETERMINATION OF MUNG BEAN TRYPSIN INHIBITOR Lys FRAGMENT-BOVINE TRYPSIN COMPLEX——MOLECULAR REPLACEMENT,ELECTRON DENSITY MAP AT 3.0 ■ RESOLUTION

The orientation and position of the trypsin molecule in the complex crystal cell mung bean trypsin inhibitor Lys fragment (MBILF)-bovine trypsin (BTRY) have been successfully determined by molecular replacement method with the model of the refined bovine trypsin molecule.Starting from the BTRY coordinates which were oriented and located in the correct azimuth and position in the complex cell according to the result from rotation function and translation function, sim-weighted Fourier map with coefficients 2|F_o|-|F_c| at 3.0 resolution was calculated.Besides the electron density which is obviously attributed to itself, in the vicinity of the active site of BTRY the dense contour levels corresponding to the MBILF and its boundary could be clearly seen in this map. The size of MBILF was approximately estimated at 15×15×25.