Model peptides containing the 3-sulfanyl-norbornene amino acid, a conformationally constrained cysteine analogue effective inducer of 310-helix secondary structures
Clerici, Francesca; Ruffoni, Alessandro; Contini, Alessandro; Soave, Raffaella; Lo Presti, Leonardo; Esposto, Irene; nava, donatella; Pellegrino, Sara; Gelmi, Maria Luisa; maffucci, irene; RSC Adv.  (2015) –; doi:10.1039/C5RA03805G

data_7220025
_publ_section_title
;
 Model peptides containing the 3-sulfanyl-norbornene amino acid, a
 conformationally constrained cysteine analogue effective inducer of
 310-helix secondary structures
;
_journal_name_full               'RSC Adv.'
_journal_paper_doi               10.1039/C5RA03805G
_journal_year                    2015
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C20 H28 N2 O3 S'
_chemical_formula_sum            'C20 H28 N2 O3 S'
_chemical_formula_weight         376.50
_chemical_name_systematic
;
  (1S,2R,3R,4R)-ethyl 2-((S)-2-aminopropanamido)-3-
(benzylthio)bicyclo[2.2.1]heptane-2-carboxylate
;
_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_conform_dict_location     ftp://ftp.iucr.org/pub/cif_core.dic
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.4
_audit_creation_date             15/02/2014
_audit_creation_method           SHELXL-97
_audit_update_record
;
2014-02-28 deposited with the CCDC.
2015-03-26 downloaded from the CCDC.
;
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.545(2)
_cell_length_b                   13.276(3)
_cell_length_c                   13.627(3)
_cell_measurement_reflns_used    4277
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      19.1
_cell_measurement_theta_min      2.3
_cell_volume                     2088.6(8)
_computing_cell_refinement       'SAINT+ (Bruker AXS, Madison (USA) m1994-1996)'
_computing_data_collection       'SAINT+ (Bruker AXS, Madison (USA) 1994-1996)'
_computing_data_reduction        'SAINT+ (Bruker AXS, Madison (USA) 1994-1996)'
_computing_molecular_graphics    'Diamond v3.2i (Brandenburg, 2012)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker AXS APEX CCD area-detector'
_diffrn_measurement_method       \w-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  0.0438
_diffrn_reflns_av_sigmaI/netI    0.0308
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            27663
_diffrn_reflns_theta_full        27.51
_diffrn_reflns_theta_max         27.51
_diffrn_reflns_theta_min         2.14
_exptl_absorpt_coefficient_mu    0.175
_exptl_absorpt_correction_T_max  0.746
_exptl_absorpt_correction_T_min  0.663
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'TWINABS-2007/4; Sheldrick, 2004'
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    1.197
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             808
_exptl_crystal_size_max          0.23
_exptl_crystal_size_mid          0.18
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.286
_refine_diff_density_min         -0.243
_refine_diff_density_rms         0.033
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.03(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.019
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     242
_refine_ls_number_reflns         4800
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.019
_refine_ls_R_factor_all          0.0738
_refine_ls_R_factor_gt           0.0468
_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^)+(0.0553P)^2^+0.3574P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1082
_refine_ls_wR_factor_ref         0.1231
_reflns_number_gt                3447
_reflns_number_total             4800
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c5ra03805g2.cif
_cod_data_source_block           compound7
_cod_original_cell_volume        2088.6(7)
_cod_database_code               7220025