Sequence-Specific Unusual (1→2)-Type Helical Turns in α/β-Hybrid Peptides
Panchami Prabhakaran; Sangram S. Kale; Vedavati G. Puranik; P. R. Rajamohanan; Olga Chetina; Judith A. K. Howard; Hans-Jörg Hofmann; Gangadhar J. Sanjayan; Journal of the American Chemical Society 130 (2008) 17743–17754; doi:10.1021/ja804297f

data_4108914
_publ_contact_author_address
;
Chemistry Department,
University of Durham,
South Rd.,
Durham
DH1 3LE
UK
;
_publ_contact_author_email       olga.chetina@durham.ac.uk
_publ_contact_author_fax         '0191 384 4737'
_publ_contact_author_name        'Dr. Olga Chetina'
_publ_contact_author_phone       '0191 334 2004'
_publ_section_title
;
 Sequence-Specific Unusual (1\\rightarrow2)-Type Helical Turns in
 \a/\b-Hybrid Peptides
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              17743
_journal_page_last               17754
_journal_paper_doi               10.1021/ja804297f
_journal_volume                  130
_journal_year                    2008
_chemical_formula_moiety         'C24 H29 N3 O6'
_chemical_formula_sum            'C24 H29 N3 O6'
_chemical_formula_weight         455.50
_chemical_melting_point          449(1)
_chemical_name_common            peptide
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 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                   10.1637(6)
_cell_length_b                   15.6505(8)
_cell_length_c                   15.0116(9)
_cell_measurement_reflns_used    4647
_cell_measurement_temperature    273(2)
_cell_measurement_theta_max      22.169
_cell_measurement_theta_min      2.388
_cell_volume                     2387.8(2)
_computing_cell_refinement       'BRUKER SAINT'
_computing_data_collection       'BRUKER SMART'
_computing_data_reduction        'BRUKER SAINT'
_computing_molecular_graphics    'SHELXTL, PyMOL and PLATON'
_computing_publication_material  SHELXTL
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      273(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device       'Bruker Smart APEX'
_diffrn_measurement_device_type  'CCD Area Detector'
_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  0.0399
_diffrn_reflns_av_sigmaI/netI    0.0316
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            19877
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.39
_exptl_absorpt_coefficient_mu    0.092
_exptl_absorpt_correction_T_max  0.9847
_exptl_absorpt_correction_T_min  0.9534
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Bruker SADABS'
_exptl_crystal_colour            colouless
_exptl_crystal_density_diffrn    1.267
_exptl_crystal_description       plate
_exptl_crystal_F_000             968
_exptl_crystal_size_max          0.52
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.17
_refine_diff_density_max         0.112
_refine_diff_density_min         -0.099
_refine_diff_density_rms         0.024
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.9(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.031
_refine_ls_hydrogen_treatment    riding
_refine_ls_matrix_type           full
_refine_ls_number_parameters     304
_refine_ls_number_reflns         4192
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.031
_refine_ls_R_factor_all          0.0427
_refine_ls_R_factor_gt           0.0354
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0415P)^2^+0.1716P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0821
_refine_ls_wR_factor_ref         0.0863
_reflns_number_gt                3676
_reflns_number_total             4192
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja804297f_si_004.cif
_cod_data_source_block           C24H29N3O6compoundppy_omenew
_cod_original_cell_volume        2387.9(2)
_cod_database_code               4108914