延胡索乙素的晶体及分子结构

本文报导用直接法测定延胡索乙素游离碱的晶体结构。晶体所属的空间群为P2_12_12_1,每个单胞中含有四个分子,晶胞参数为a=22.296,b=11.795,c=7·452。用块对角矩阵最小二乘方对全部非氢原子坐标及其各向异性温度因子,对氢原子坐标及其各向同性温度因子进行修正,最后R因子为0.045。本文对于分子的某些结构特征作了讨论。     

去B链N端二肽(B_(1—2))猪胰岛素晶体结构的研究——单晶培养及X射线晶体学的分析

利用微量过饱和静置法,在柠檬酸缓冲液中培养出可供X射线结构分析用的去B链N端二肽(B_(1-2))猪胰岛素单晶。晶体衍射分辨率达到4.0A以上。晶体属于立方晶系,a=97.43A,空间群为P4_132(或P4_332),每个结晶学不对称单位含两个或三个去B链N端二肽(B_(1-2))猪胰岛素分子。本文对单位晶胞内六聚体之间和二聚体之间可能的堆积方式进行了讨论。     

PRELIMINARY CRYSTALLOGRAPHIC ANALYSIS OF DESHEXAPEPTIDE (B25—B30) INSULIN

Satisfactory single crystals of deshexapeptide(B25—B30) insulin for X-ray crystal structure analysis have been grown in citrate buffer by the method of hanging-drop gas phase diffusion. The crystal belongs to the monoclinic system with space group C2. The unit cell constants are α=42.6, b=37.9, c=27.2, β=125.4 and there is only one molecule of deshexapeptide insulin in an asymmetric unit.     

钩吻素溴氢酸盐的晶体结构及其分子的绝对构型

利用Patterson和Fourier法测定了生物碱钩吻素溴氢酸盐(C₂₀H₂₂N₂O·HBr)的晶体结构,经全矩阵最小二乘法修正,偏离因子R=0.067,晶体属正交晶系;晶胞参数为α=14.307?,b=12.053?,c=9.862?;晶胞中分子数z=4;空间群为D₂⁴-P2₁ 2₁ 2₁,在非氢原子的坐标和各向异性热运动参数的 关键词：     

硝酸镧与大环聚醚l,8-萘并-16-冠-5络合物的分子和晶体的结构

硝酸镧与大环聚醚1,8-萘并-16-冠-5络合物晶体属单斜晶系,空间群P2₁/n,晶胞中含四个分子,晶胞参数a=15.455Å,b=11.512Å,c=13.825Å,β=109.6°.强度数据由PW-1100四圆衍射仪收集,采用CuK_a辐射.结构用重原子法求解,并用全矩阵最小二乘法对全部原子的坐标参数及其各向同性温度因子进行了修,最后的R因子为0.108.镧离子的配位数为11,其中5个醚氧在镧离子的一侧,La-O键长2.59～2.78Å,而三个双齿配位硝酸根中的6个氧在另一侧,La-O键长2.59～2.63Å.     

THE GROWTH OF SINGLE CRYSTAL AND THE DETERMINATION OF CRYSTALLOGRAPHIC PA RAMETERS OF (L-TRYPTOPHAN)~(A1)-INSULIN AND (D-TRYPTOPHAN)~(A1)-INSULIN

The crystal-growing conditions and the results of preliminary X-ray crystallographic analysis of (L-Try)~(A1)-insulin and (D-Try)~(A1)-insulin are reported. The single crystals of this pair of insulin analogue suitable for X-ray diffraction analysis have been grown in the citrate buffer system by still-setting method. They both belong to the trigonal system with space group R3. The parameters of the unit cell (L-Trp)~(A1)-insulin are αH= 80.31, cH= 37.45 and those of (D-Trp)~(A1)-insulin αH = 79.48, cH = 43.81. There are two molecules in an asymmetric unit. The obtained results are discussed.     

Preliminary crystallographic analysis of recombinant chicken liver fructose-2,6-bisphosphatase

The bisphosphatase domain of chicken liver 6-phosphofructo-2-kinase/fructose-2,6-bisphos-phosphatase was expressed in high yield Escherichia coli and purified to homogeneity. Single crystals of chicken liver bisphophatase domain suitable for X-ray diffraction were obtained by the hanging drop vapor diffusion method. The crystals belong to tetragonal space group P41212 or P43213 with two molecules per asymmetric unit. The determined cell dimensions are: a=b= 10.02 nm, c= 13.98 nm, α=β=г=90°. EHffraction data were collected on Weissenberg camera with synchrotron radiation at 0.32nm resolution.     

MOLECULAR STRUCTURE AND ABSOLUTE CONFIGURATION OF SUBEROGORGIN

In the present paper it is reported that the molecular structure and absolute configuration of poisonous suberogorgin are determined by using X-ray diffraction method. The crystal of suberogorgin belongs to orthogonal system with space group D_2~4-P2_12_12_1. The crystallographic parameters are: a=16.135, b=13.189, c=12.901, Z=8. The initial model of the crystal structure was solved by the direct method. The refinement of the strueture parameters was carried out by using the least square method and led to a final R-factor of 0.056. In accordance with the molecular structure of suberogorgin mentioned above, the solvent effect of NMR has been further discussed and the relationship between the molecular structure of suberogorgin and its toxicity has also been preliminarily investigated.