The determination of deshexapeptide(B25-B30)insulin(DHI)was divided into two steps.At the first step,the rough structure model of DHI molecule was determined by using the molecularreplacement method associated with th...The determination of deshexapeptide(B25-B30)insulin(DHI)was divided into two steps.At the first step,the rough structure model of DHI molecule was determined by using the molecularreplacement method associated with the molecular close-packing method at 0.30 nm resolution based on the re-flection data collected on four-cycle diffractometer.At the second step,the DHI model was adjusted and re-fined at 0.25nm resolution based on the data collected on Area Detector.40 water molecules were determinedduring the refinement,the final R-factor is 0.185 with R.M.S.deviation of 0.002nm for bond lengths and 1.9°for bond angles.The differences in conformation and function of DHI with other insulin analogues werecompared and discussed.展开更多
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 mon...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.展开更多
Based on the molecule-packing theory, we defined a molecule-packing function express-ing the compatibility of packing among the symmetry-related molecules in a unit cell. Acomputer program imitating the close-packing ...Based on the molecule-packing theory, we defined a molecule-packing function express-ing the compatibility of packing among the symmetry-related molecules in a unit cell. Acomputer program imitating the close-packing of molecules in the objective crystal latticeand giving the function value of each rotation and translation of the molecule in the unitcell was performed, and it therefore made the close-packing of molecules expressquantitatively. This method not only could judge a correct solution from several peaks ofthe rotation or translation function but it may also independently, quantitatively and quicklysolve some specific problems of rotation and translation. Using known structure of despenta-peptide (B26--B30) insulin as an example, the effectiveness of this method and its programwas inspected, and this method was successfully applied to solving the translation problem ofthe unknown structure of deshexapeptide (B25--B30) insulin. The molecular close-packingmethod proved by the results of R--search and electron density maps is relatively independ-ent of the molecular replacement method, though an effective complement of it.展开更多
基金the Foundation of Chinese Academy of Sciencesthe National Natural Science Foundation of China.
文摘The determination of deshexapeptide(B25-B30)insulin(DHI)was divided into two steps.At the first step,the rough structure model of DHI molecule was determined by using the molecularreplacement method associated with the molecular close-packing method at 0.30 nm resolution based on the re-flection data collected on four-cycle diffractometer.At the second step,the DHI model was adjusted and re-fined at 0.25nm resolution based on the data collected on Area Detector.40 water molecules were determinedduring the refinement,the final R-factor is 0.185 with R.M.S.deviation of 0.002nm for bond lengths and 1.9°for bond angles.The differences in conformation and function of DHI with other insulin analogues werecompared and discussed.
基金Project supported by the National Natural Science Foundation of China.
文摘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.
基金Project supported by the Foundation of Chinese Academy of Sciences and the National Natural Science Foundation of China.
文摘Based on the molecule-packing theory, we defined a molecule-packing function express-ing the compatibility of packing among the symmetry-related molecules in a unit cell. Acomputer program imitating the close-packing of molecules in the objective crystal latticeand giving the function value of each rotation and translation of the molecule in the unitcell was performed, and it therefore made the close-packing of molecules expressquantitatively. This method not only could judge a correct solution from several peaks ofthe rotation or translation function but it may also independently, quantitatively and quicklysolve some specific problems of rotation and translation. Using known structure of despenta-peptide (B26--B30) insulin as an example, the effectiveness of this method and its programwas inspected, and this method was successfully applied to solving the translation problem ofthe unknown structure of deshexapeptide (B25--B30) insulin. The molecular close-packingmethod proved by the results of R--search and electron density maps is relatively independ-ent of the molecular replacement method, though an effective complement of it.
