Probing the Role of the C-H...O Hydrogen Bond Stabilized Polypeptide Chain Reversal at the C-terminus of Designed Peptide Helices. Structural Characterization of Three Decapeptides
Subrayashastry Aravinda; Narayanaswamy Shamala; Abhishek Bandyopadhyay; Padmanabhan Balaram; Journal of the American Chemical Society 125 (2003) 15065–15075; doi:10.1021/ja0372762

data_4114461
_publ_section_title
;
 Probing the Role of the C-H...O Hydrogen Bond Stabilized Polypeptide
 Chain Reversal at the C-terminus of Designed Peptide Helices. Structural
 Characterization of Three Decapeptides
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              15065
_journal_page_last               15075
_journal_paper_doi               10.1021/ja0372762
_journal_volume                  125
_journal_year                    2003
_chemical_formula_moiety         '2(C52 H94 N10 O13) * 3 H2O'
_chemical_formula_sum            'C52 H97 N10 O14.5'
_chemical_formula_weight         1094.37
_chemical_name_common
;
Boc-Leu-Aib-Val-D-Ala-Leu-Aib-Val-D-Ala-D-Leu-Aib-OMe
;
_chemical_name_systematic
; 
 t-Butyloxycarbonyl-leucyl-(alpha-aminoisobutyryl)-valyl-D-alanyl-leucyl-
 (alpha-aminoisobutyryl)-valyl-D-alanyl-D-leucyl-(alpha-aminoisobutyryl)
 methyl ester trihydrate
;
_space_group_IT_number           96
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'P 4nw 2abw'
_symmetry_space_group_name_H-M   'P 43 21 2'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            16
_cell_length_a                   25.115(4)
_cell_length_b                   25.115(4)
_cell_length_c                   43.709(10)
_cell_measurement_temperature    293(2)
_cell_volume                     27570(9)
_computing_data_collection       SMART
_computing_data_reduction        SAINT
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXD (Sheldrick and Schneider 2001)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean NA
_diffrn_measured_fraction_theta_full 0.968
_diffrn_measured_fraction_theta_max 0.968
_diffrn_measurement_device_type  'BRUKER AXS SMART APEX CCD with Mo source'
_diffrn_measurement_method       'omega scan'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.2882
_diffrn_reflns_av_sigmaI/netI    0.2572
_diffrn_reflns_limit_h_max       30
_diffrn_reflns_limit_h_min       -32
_diffrn_reflns_limit_k_max       31
_diffrn_reflns_limit_k_min       -30
_diffrn_reflns_limit_l_max       53
_diffrn_reflns_limit_l_min       -55
_diffrn_reflns_number            355061
_diffrn_reflns_theta_full        27.10
_diffrn_reflns_theta_max         27.10
_diffrn_reflns_theta_min         1.62
_exptl_absorpt_coefficient_mu    0.077
_exptl_crystal_colour            'colour less'
_exptl_crystal_density_diffrn    1.052
_exptl_crystal_description       rectangular
_exptl_crystal_F_000             9472
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.2
_refine_diff_density_max         0.354
_refine_diff_density_min         -0.176
_refine_diff_density_rms         0.045
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.7(14)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.795
_refine_ls_hydrogen_treatment    'riding on C or N to which bonded'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1378
_refine_ls_number_reflns         29024
_refine_ls_number_restraints     4
_refine_ls_restrained_S_all      0.796
_refine_ls_R_factor_all          0.3442
_refine_ls_R_factor_gt           0.0699
_refine_ls_shift/su_max          13.308
_refine_ls_shift/su_mean         0.208
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0962P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1565
_refine_ls_wR_factor_ref         0.2334
_reflns_number_gt                6693
_reflns_number_total             29024
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja0372762si20030715_034742_2.cif
_cod_data_source_block           da-10
_cod_original_formula_sum        'C52 H97 N10 O14.50'
_cod_database_code               4114461