Protein secondary structure mimetics: crystal conformations of α/γ4-hybrid peptide12-helices with proteinogenic side chains and their analogy with α- and β-peptide helices.
Jadhav, Sandip V.; Bandyopadhyay, Anupam; Gopi, Hosahudya N.; Organic & biomolecular chemistry 11 (2013) 509–514; doi:10.1039/c2ob26805a

data_7152776
_publ_section_title
;
 Protein secondary structure mimetics: crystal conformations of
 \a/\g4-hybrid peptide12-helices with proteinogenic side chains and their
 analogy with \a- and \b-peptide helices.
;
_journal_issue                   3
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              509
_journal_page_last               514
_journal_paper_doi               10.1039/c2ob26805a
_journal_volume                  11
_journal_year                    2013
_chemical_absolute_configuration ad
_chemical_compound_source        synthesis
_chemical_formula_moiety         'C48 H66 N8 O8'
_chemical_formula_sum            'C48 H66 N8 O9'
_chemical_formula_weight         899.09
_chemical_name_common            'alpha-gamma peptide'
_chemical_name_systematic        'alpha-gamma peptide'
_space_group_IT_number           1
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  'P 1'
_symmetry_space_group_name_H-M   'P 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                68.89(3)
_cell_angle_beta                 85.74(3)
_cell_angle_gamma                71.36(3)
_cell_formula_units_Z            1
_cell_length_a                   9.354(10)
_cell_length_b                   12.179(13)
_cell_length_c                   13.950(15)
_cell_measurement_temperature    100(2)
_cell_volume                     1403(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_pressure         101.325
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_device_type  'Bruker SMART APEX2 area detector'
_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  0.0501
_diffrn_reflns_av_sigmaI/netI    0.1021
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            24197
_diffrn_reflns_theta_full        28.28
_diffrn_reflns_theta_max         28.28
_diffrn_reflns_theta_min         1.57
_exptl_absorpt_coefficient_mu    0.074
_exptl_absorpt_correction_T_max  0.985
_exptl_absorpt_correction_T_min  0.974
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.064
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             482
_exptl_crystal_recrystallization_method MeOH/Water
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.2
_platon_squeeze_details
;
The volume occupied by solvent is 29 percent of the unit cell.
;
_refine_diff_density_max         0.248
_refine_diff_density_min         -0.257
_refine_diff_density_rms         0.056
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.6(18)
_refine_ls_extinction_coef       0.032(6)
_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   0.771
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     569
_refine_ls_number_reflns         10395
_refine_ls_number_restraints     327
_refine_ls_restrained_S_all      0.762
_refine_ls_R_factor_all          0.1364
_refine_ls_R_factor_gt           0.0823
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.2000P)^2^+0.1787P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2342
_refine_ls_wR_factor_ref         0.2723
_reflns_number_gt                4880
_reflns_number_total             10395
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2ob26805a.txt
_cod_data_source_block           Peptide_P2
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 
;
_cod_original_sg_symbol_H-M      P1
_cod_database_code               7152776