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_4108912
_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_absolute_configuration syn
_chemical_formula_moiety         'C29 H34 N4 O7, 0.5H2O'
_chemical_formula_sum            'C29 H35 N4 O7.5'
_chemical_formula_weight         559.61
_chemical_melting_point          454(1)
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      4
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_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-09152005. 
;
_cell_angle_alpha                90.00
_cell_angle_beta                 93.158(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   9.6923(5)
_cell_length_b                   9.4608(4)
_cell_length_c                   15.6706(7)
_cell_measurement_reflns_used    999
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      29.00
_cell_measurement_theta_min      1.30
_cell_volume                     1434.76(12)
_computing_cell_refinement       'SAINT Ver. 6.45  (Bruker-AXS, 2003)'
_computing_data_collection       'SMART Ver. 5.630 (Bruker-AXS, 2003)'
_computing_data_reduction        'SAINT Ver. 6.45'
_computing_molecular_graphics    'SHELXTL Ver. 6.14'
_computing_publication_material  'SHELXTL Ver. 6.14'
_computing_structure_refinement  'SHELXTL Ver. 6.14'
_computing_structure_solution    'SHELXTL Ver. 6.14 (Bruker-AXS, 2003)'
_diffrn_ambient_temperature      120(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker SMART CCD 6000'
_diffrn_measurement_method       '0.30\% \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           Mo-K\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1064
_diffrn_reflns_av_sigmaI/netI    0.0754
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            17934
_diffrn_reflns_theta_full        29.00
_diffrn_reflns_theta_max         29.00
_diffrn_reflns_theta_min         1.30
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.094
_exptl_absorpt_correction_type   none
_exptl_absorpt_process_details
;
?
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.295
_exptl_crystal_description       block
_exptl_crystal_F_000             594
_exptl_crystal_size_max          0.24
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.07
_refine_diff_density_max         0.463
_refine_diff_density_min         -0.223
_refine_diff_density_rms         0.046
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.9(11)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.960
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     375
_refine_ls_number_reflns         4027
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      0.960
_refine_ls_R_factor_all          0.0738
_refine_ls_R_factor_gt           0.0429
_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^)+(0.0500P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0949
_refine_ls_wR_factor_ref         0.1058
_reflns_number_gt                2787
_reflns_number_total             4027
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ja804297f_si_002.cif
_cod_data_source_block           ibin
_cod_original_sg_symbol_Hall     'P 2yb       '
_cod_original_sg_symbol_H-M      'P 1 21 1 '
_cod_original_formula_sum        'C29 H35 N4 O7.50'
_cod_database_code               4108912