Text: THE STRUCTURE OF THE 3-KETOSTEROID ISOMERASE 19-NORTESTOSTERONE HEMISUCCINATE ( 19-NTHS) COMPLEX WAS DETERMINED FROM BOTH 2D NOESY, 3D NOESY AND TRIPLE RESONANCE NMR SPECTRA ON AN UNLABELED ...Text: THE STRUCTURE OF THE 3-KETOSTEROID ISOMERASE 19-NORTESTOSTERONE HEMISUCCINATE ( 19-NTHS) COMPLEX WAS DETERMINED FROM BOTH 2D NOESY, 3D NOESY AND TRIPLE RESONANCE NMR SPECTRA ON AN UNLABELED SAMPLE (2D NOESY), 15N-LABELED, 13C-, 15N-UNIFORMLY LABELED, AND/OR 13C-,15N/15N-HETEROLABELED ISOMERASE WITH 1.1 MM 19-NTHS. 3D NOESY AND TRIPLE RESONACE SPECTRA ON THE 15N-UNIFORMLY LABELED AND 13C-,15N-UNIFORMLY SAMPLES WERE USED FOR 1H, 15N,13C ASSIGNMENTS AS WELL AS STRUCTURAL INFORMATION FOR EACH SUBUNIT. THE 1H-13C-FILTERED NOESY-HSQC OF A 13C, 15N/15N-HETEROLABELED SAMPLE PROVIDED CRITICAL NOES BETWEEN THE IDENTICAL MONOMERS OF THE HOMODIMER WHICH LED TO THE SOLUTION STRUCTURE OF KSI COMPLEXED TO 19-NTHS.
手法: DISTANCE GEOMETRY, SIMULATED ANNEALING, REFINEMENT CALCULATIONS ソフトェア番号: 1 詳細: DURING THE REFINEMENT, THE NON-BONDED INTERACTIONS WERE MODELED ONLY BY A QUADRATIC REPULSIVE ENERGY TERM, WHILE THE ATTRACTIVE COMPONENT OF THE LENNARD- JONES POTENTIAL AND THE ELECTROSTATIC ...詳細: DURING THE REFINEMENT, THE NON-BONDED INTERACTIONS WERE MODELED ONLY BY A QUADRATIC REPULSIVE ENERGY TERM, WHILE THE ATTRACTIVE COMPONENT OF THE LENNARD- JONES POTENTIAL AND THE ELECTROSTATIC ENERGY WERE TURNED OFF. AT THE FINAL STAGES OF REFINEMENT, A SQUARE-WELL POTENTIAL ENERGY FUNCTION WAS USED FOR THE NOE AND THE DIHEDRAL ANGLE RESTRANTS WITH A FORCE OF 500 KCAL MOL-1 ANG-2 AND 200 KCAL MOL-1 RAD-2, RESPECTIVELY. OF THE 120 EMBEDDED SUBSTRUCTURES, 60 CONVERGED TO ACCEPTABLE STRUCTURES WITH NOE VIOLATION EQUAL OR LESS THAN 0.5ANG. OF THESE, 15 BEST STRUCTURES WITH NOE VIOLATIONS EQUAL OR LESS THAN 0.35 ANG AND DIHEDRAL VIOLATION < 5 DEG WERE SELECTED. MODEL 1 (STRUCTURE 1) OF THE 15 STRUCTURES OF THE KSI-19NTHS COMPLEX IS THE LOWEST ENERGY STRUCTURE.
NMRアンサンブル
コンフォーマー選択の基準: NOE VIOLATION =< 0.35A AND DIHEDRAL VIOLATION < 5 DEG. 計算したコンフォーマーの数: 120 / 登録したコンフォーマーの数: 15