Comparative conformational analysis of peptides based on the two Cα-tetrasubstituted, Cβ-branched, chiral α-amino acids (αMe)Dip and (αMe)Val †
Lapeña, Yolanda; Lopez, Pilar; Cativiela, Carlos; Kaptein, Bernard; Broxterman, Quirinus B.; Kamphuis, Johan; Mossel, Eric; Peggion, Cristina; Formaggio, Fernando; Crisma, Marco; Toniolo, Claudio; Journal of the Chemical Society, Perkin Transactions 2  (2000) 631–; doi:10.1039/a909856i

data_7213248
_publ_section_title
;
 Comparative conformational analysis of peptides based on the two
 C\a-tetrasubstituted, C\b-branched, chiral \a-amino acids (\aMe)Dip and
 (\aMe)Val&#x200A;&#x2020;
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_journal_issue                   4
_journal_name_full
'Journal of the Chemical Society, Perkin Transactions 2'
_journal_page_first              631
_journal_paper_doi               10.1039/a909856i
_journal_year                    2000
_chemical_formula_moiety         'C30 H47 N5 O8, C H4 O'
_chemical_formula_sum            'C31 H51 N5 O9'
_chemical_formula_weight         637.77
_chemical_name_systematic
; 
 Z-L-(alphaMe)Val-(L-Ala)2-L-(alphaMe)Val-L-Ala-OMe
 methanol solvate
;
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_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           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 107.8(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   10.080(2)
_cell_length_b                   17.853(3)
_cell_length_c                   10.185(2)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      24
_cell_measurement_theta_min      14
_cell_volume                     1745.1(11)
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1985)'
_diffrn_ambient_temperature      293(2)
_diffrn_measurement_device       'Philips PW1100 diffractometer'
_diffrn_measurement_method       '\q-2\q scan'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54180
_diffrn_reflns_av_R_equivalents  0.0131
_diffrn_reflns_av_sigmaI/netI    0.0096
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            2843
_diffrn_reflns_theta_max         60.03
_diffrn_reflns_theta_min         4.56
_diffrn_standards_decay_%        1.5
_diffrn_standards_interval_count 100
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.736
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.214
_exptl_crystal_description       prism
_exptl_crystal_F_000             688
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.247
_refine_diff_density_min         -0.134
_refine_diff_density_rms         0.029
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.04(28)
_refine_ls_extinction_coef       0.0169(9)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_all   1.074
_refine_ls_goodness_of_fit_obs   1.098
_refine_ls_hydrogen_treatment    riding
_refine_ls_matrix_type           fullcycle
_refine_ls_number_parameters     395
_refine_ls_number_reflns         2687
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.078
_refine_ls_restrained_S_obs      1.098
_refine_ls_R_factor_all          0.0396
_refine_ls_R_factor_obs          0.0349
_refine_ls_shift/esd_max         -0.072
_refine_ls_shift/esd_mean        0.014
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0669P)^2^+0.3526P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1079
_refine_ls_wR_factor_obs         0.1057
_reflns_number_observed          2514
_reflns_number_total             2689
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            a909856isup1.cif
_cod_data_source_block           ctf12
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0669P)^2^+0.3526P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to
'w=1/[\s^2^(Fo^2^)+(0.0669P)^2^+0.3526P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        1745.1(6)
_cod_original_sg_symbol_H-M      P2(1)
_cod_database_code               7213248