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_4114460
_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         'C51 H92 N10 O13 * H2O'
_chemical_formula_sum            'C51 H94 N10 O14'
_chemical_formula_weight         1071.36
_chemical_name_common
;
Boc-Leu-Aib-Val-Gly-Leu-Aib-Val-D-Ala-D-Leu-Aib-OMe
;
_chemical_name_systematic
; 
 t-Butyloxycarbonyl-leucyl-(alpha-aminoisobutyryl)-valyl-glycyl-leucyl-
 (alpha-aminoisobutyryl)-valyl-D-alanyl-D-leucyl-(alpha-aminoisobutyryl)
 methyl ester monohydrate
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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            4
_cell_length_a                   13.818(2)
_cell_length_b                   21.595(9)
_cell_length_c                   21.928(8)
_cell_measurement_temperature    293(2)
_cell_volume                     6543(4)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'Shake and Bake (Miller et al 1994)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'CAD4 diffractometer with Cu source'
_diffrn_measurement_method       'omega - two theta'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54180
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    0.1010
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            4559
_diffrn_reflns_theta_full        55.02
_diffrn_reflns_theta_max         55.02
_diffrn_reflns_theta_min         2.87
_diffrn_standards_decay_%        3
_diffrn_standards_interval_count 100
_diffrn_standards_interval_time  3600
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    0.650
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'colour less'
_exptl_crystal_density_diffrn    1.088
_exptl_crystal_description       'thin plates'
_exptl_crystal_F_000             2328
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.23
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.305
_refine_diff_density_min         -0.266
_refine_diff_density_rms         0.069
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.4(10)
_refine_ls_extinction_coef       0.0015(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.130
_refine_ls_hydrogen_treatment    'riding on C or N to which bonded'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     675
_refine_ls_number_reflns         4559
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.130
_refine_ls_R_factor_all          0.1853
_refine_ls_R_factor_gt           0.1059
_refine_ls_shift/su_max          0.315
_refine_ls_shift/su_mean         0.034
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1216P)^2^+9.6722P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2367
_refine_ls_wR_factor_ref         0.3042
_reflns_number_gt                2428
_reflns_number_total             4559
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja0372762si20030715_034742_1.cif
_cod_data_source_block           lgd-10
_cod_database_code               4114460