A Synthetic Zipper Peptide Motif Orchestrated via Co-operative Interplay of Hydrogen Bonding, Aromatic Stacking, and Backbone Chirality
Roshna V. Nair; Sanjeev Kheria; Suresh Rayavarapu; Amol S. Kotmale; Bharatam Jagadeesh; Rajesh G. Gonnade; Vedavati G. Puranik; Pattuparambil R. Rajamohanan; Gangadhar J. Sanjayan; Journal of the American Chemical Society 135 (2013) 11477–11480; doi:10.1021/ja405455g

data_4120238
_publ_section_title
;
 A Synthetic Zipper Peptide Motif Orchestrated via Co-operative Interplay
 of Hydrogen Bonding, Aromatic Stacking, and Backbone Chirality
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              11477
_journal_page_last               11480
_journal_paper_doi               10.1021/ja405455g
_journal_volume                  135
_journal_year                    2013
_chemical_absolute_configuration rmad
_chemical_formula_moiety
'C38H37Br1N6O8, 0.5(C4H8O2), 0.25(CH3oh), 1.75(H2O)'
_chemical_formula_sum            'C40.25 H45.5 Br N6 O9'
_chemical_formula_weight         837.24
_chemical_name_systematic
; 
 ? 
;
_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                90.701(8)
_cell_angle_beta                 105.291(8)
_cell_angle_gamma                104.722(8)
_cell_formula_units_Z            4
_cell_length_a                   12.6540(18)
_cell_length_b                   16.041(2)
_cell_length_c                   20.114(3)
_cell_measurement_reflns_used    9563
_cell_measurement_temperature    97(2)
_cell_measurement_theta_max      22.37
_cell_measurement_theta_min      2.26
_cell_volume                     3795.2(9)
_computing_cell_refinement       'SAINT (Bruker, 2003)'
_computing_data_collection       'SMART (Bruker, 2003)'
_computing_data_reduction        'SAINT (Bruker, 2003)'
_computing_molecular_graphics    'SHELXTL (Bruker, 2003)'
_computing_publication_material  'SHELXTL (Bruker, 2003), platon'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      97(2)
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device       'Bruker Smart APEX'
_diffrn_measurement_device_type  'CCD Area Detector'
_diffrn_measurement_method       'Phi and 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  0.0671
_diffrn_reflns_av_sigmaI/netI    0.0959
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            118413
_diffrn_reflns_theta_full        28.52
_diffrn_reflns_theta_max         28.52
_diffrn_reflns_theta_min         1.73
_exptl_absorpt_coefficient_mu    1.149
_exptl_absorpt_correction_T_max  0.9663
_exptl_absorpt_correction_T_min  0.7391
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'BRUKER's SADABS'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.465
_exptl_crystal_description       needle
_exptl_crystal_F_000             1744
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.11
_exptl_crystal_size_min          0.03
_platon_squeeze_details
;
The unit cell contains two ethyl acetate molecules (C4H8O2) and 
another three wather molecules (H2O), which have been treated as 
a diffuse contribution to the overall scattering without 
specific atom positions 
by SQUEEZE/PLATON.
;
_refine_diff_density_max         1.743
_refine_diff_density_min         -2.326
_refine_diff_density_rms         0.223
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.000(15)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.514
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1903
_refine_ls_number_reflns         37772
_refine_ls_number_restraints     262
_refine_ls_restrained_S_all      1.517
_refine_ls_R_factor_all          0.1636
_refine_ls_R_factor_gt           0.1384
_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^)+(0.2000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.3860
_refine_ls_wR_factor_ref         0.3983
_reflns_number_gt                27315
_reflns_number_total             37772
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja405455g_si_002_2.cif
_cod_data_source_block           comp_4
_cod_original_cell_volume        3795.1(9)
_cod_original_formula_sum        'C40.25 H45.50 Br N6 O9'
_cod_database_code               4120238