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_4104251
_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         'C59 H92 N8 O11 + C4 H8 O1'
_chemical_formula_sum            'C63 H100 N8 O12'
_chemical_formula_weight         1161.51
_chemical_name_common            Boc-Leu-Phe-Val-Aib-Gpn-Leu-Phe-Val-OMe
_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                   9.5580(11)
_cell_length_b                   26.278(3)
_cell_length_c                   27.434(3)
_cell_measurement_temperature    293(2)
_cell_volume                     6890.5(13)
_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 0.988
_diffrn_measured_fraction_theta_max 0.988
_diffrn_measurement_device_type  'BRUKER AXS SMART APEX CCD with Mo source'
_diffrn_measurement_method       '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  0.0921
_diffrn_reflns_av_sigmaI/netI    0.0457
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            29753
_diffrn_reflns_theta_full        19.78
_diffrn_reflns_theta_max         19.78
_diffrn_reflns_theta_min         1.48
_exptl_absorpt_coefficient_mu    0.077
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.120
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       rectangular
_exptl_crystal_F_000             2520
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.1
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.315
_refine_diff_density_min         -0.243
_refine_diff_density_rms         0.059
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -10(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.087
_refine_ls_hydrogen_treatment    'riding on C or N atom to which attached'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     736
_refine_ls_number_reflns         3493
_refine_ls_number_restraints     23
_refine_ls_restrained_S_all      1.086
_refine_ls_R_factor_all          0.1450
_refine_ls_R_factor_gt           0.1235
_refine_ls_shift/su_max          0.629
_refine_ls_shift/su_mean         0.119
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1521P)^2^+15.4416P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2948
_refine_ls_wR_factor_ref         0.3128
_reflns_number_gt                2723
_reflns_number_total             3493
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja900618h_si_002.cif
_cod_data_source_block           lfvug8
_cod_original_cell_volume        6890.5(14)
_cod_database_code               4104251