Expanding the Peptide β-Turn in αγ Hybrid Sequences: 12 Atom Hydrogen Bonded Helical and Hairpin Turns
Sunanda Chatterjee; Prema G. Vasudev; Srinivasarao Raghothama; Chandrasekharan Ramakrishnan; Narayanaswamy Shamala; Padmanabhan Balaram; Journal of the American Chemical Society 131 (2009) 5956–5965; doi:10.1021/ja900618h

data_4104250
_publ_section_title
;
 Expanding the Peptide \b-Turn in \a\g Hybrid Sequences: 12 Atom Hydrogen
 Bonded Helical and Hairpin Turns
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              5956
_journal_page_last               5965
_journal_paper_doi               10.1021/ja900618h
_journal_volume                  131
_journal_year                    2009
_chemical_formula_moiety         'C58 H100 N8 O11'
_chemical_formula_sum            'C58 H100 N8 O11'
_chemical_formula_weight         1085.46
_chemical_name_common            Boc-Gpn-Aib-Gpn-Aib-Gpn-Aib-Gpn-Aib-OMe
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 92.783(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.9614(7)
_cell_length_b                   18.5134(11)
_cell_length_c                   29.4975(19)
_cell_measurement_temperature    293(2)
_cell_volume                     6524.4(7)
_computing_data_collection       SMART
_computing_data_reduction        SAINT
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.956
_diffrn_measured_fraction_theta_max 0.956
_diffrn_measurement_device_type  'BRUKER AXS KAPPA APEXII CCD with Mo source'
_diffrn_measurement_method       'omega and phi scans'
_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  0.4281
_diffrn_reflns_av_sigmaI/netI    0.5389
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_l_max       39
_diffrn_reflns_limit_l_min       -39
_diffrn_reflns_number            52460
_diffrn_reflns_theta_full        28.62
_diffrn_reflns_theta_max         28.62
_diffrn_reflns_theta_min         1.30
_exptl_absorpt_coefficient_mu    0.076
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.105
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       cubical
_exptl_crystal_F_000             2368
_exptl_crystal_size_max          0.1
_exptl_crystal_size_mid          0.1
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.314
_refine_diff_density_min         -0.209
_refine_diff_density_rms         0.046
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.806
_refine_ls_hydrogen_treatment    'riding on C or N atom to which attached'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     722
_refine_ls_number_reflns         15967
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.806
_refine_ls_R_factor_all          0.4058
_refine_ls_R_factor_gt           0.0731
_refine_ls_shift/su_max          0.004
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0868P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1569
_refine_ls_wR_factor_ref         0.2858
_reflns_number_gt                2692
_reflns_number_total             15967
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja900618h_si_001.cif
_cod_data_source_block           gu8
_cod_database_code               4104250