Helix Formation in Preorganized β/γ-Peptide Foldamers: Hydrogen-Bond Analogy to the α-Helix without α-Amino Acid Residues
Li Guo; Aaron M. Almeida; Weicheng Zhang; Andrew G. Reidenbach; Soo Hyuk Choi; Ilia A. Guzei; Samuel H. Gellman; Journal of the American Chemical Society 132 (2010) 7868–7869; doi:10.1021/ja103233a

data_4102537
_publ_contact_author_address
;
Department of Chemistry
University of Wisconsin-Madison
1101 University Ave
Madison, WI  53706
USA
;
_publ_contact_author_email       iguzei@chem.wisc.edu
_publ_contact_author_fax         608-262-0381
_publ_contact_author_name
;
Guzei, Ilia A. 
;
_publ_contact_author_phone       608-263-4694
_publ_section_title
;
 Helix Formation in Preorganized \b/\g-Peptide Foldamers: Hydrogen-Bond
 Analogy to the \a-Helix without \a-Amino Acid Residues
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              7868
_journal_page_last               7869
_journal_paper_doi               10.1021/ja103233a
_journal_volume                  132
_journal_year                    2010
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C50 H76 Br N5 O8'
_chemical_formula_sum            'C50 H76 Br N5 O8'
_chemical_formula_weight         955.07
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_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
;
manual editing of the CIF file 
created by SHELXTL Ver. 6.10
and processed with modiCIfer-03272007. 
;
_audit_update_record
;
2010-04-27 # Formatted by publCIF
;
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.9331(2)
_cell_length_b                   18.5573(3)
_cell_length_c                   24.7143(4)
_cell_measurement_reflns_used    9895
_cell_measurement_temperature    100(1)
_cell_measurement_theta_max      64.0996
_cell_measurement_theta_min      2.9779
_cell_volume                     5014.26(15)
_computing_cell_refinement       'SAINT Ver. 7.24A (Bruker-AXS, 2007)'
_computing_data_collection       'APEX2 Ver. 2.1-4 (Bruker-AXS, 2007)'
_computing_data_reduction        'SAINT Ver. 7.24A'
_computing_molecular_graphics    SHELXTL
_computing_publication_material  SHELXTL
_computing_structure_refinement  SHELXTL
_computing_structure_solution    'SHELXTL (Sheldrick, 2008)'
_diffrn_ambient_temperature      100(1)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'Bruker SMART APEX2 area detector'
_diffrn_measurement_method       '0.50\% \w and 0.5 \% \f scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0860
_diffrn_reflns_av_sigmaI/netI    0.0556
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            64171
_diffrn_reflns_theta_full        67.00
_diffrn_reflns_theta_max         67.64
_diffrn_reflns_theta_min         2.98
_exptl_absorpt_coefficient_mu    1.567
_exptl_absorpt_correction_T_max  0.9258
_exptl_absorpt_correction_T_min  0.7550
_exptl_absorpt_correction_type   analytical
_exptl_absorpt_process_details
;
SADABS  (Bruker-AXS, 2007)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.265
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             2040
_exptl_crystal_size_max          0.19
_exptl_crystal_size_mid          0.19
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.460
_refine_diff_density_min         -0.672
_refine_diff_density_rms         0.063
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.00(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.951
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     581
_refine_ls_number_reflns         8952
_refine_ls_number_restraints     18
_refine_ls_restrained_S_all      0.950
_refine_ls_R_factor_all          0.0915
_refine_ls_R_factor_gt           0.0576
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0973P)^2^+4.4518P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1434
_refine_ls_wR_factor_ref         0.1695
_reflns_number_gt                6485
_reflns_number_total             8952
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ja103233a_si_003.cif
_cod_data_source_block           gellman130
_cod_original_cell_volume        5014.25(15)
_cod_original_sg_symbol_Hall     'P 2ac 2ab   '
_cod_original_sg_symbol_H-M      'P 21 21 21 '
_cod_database_code               4102537