Triglycine (GGG) Adopts a Polyproline II (pPII) Conformation in Its Hydrated Crystal Form: Revealing the Role of Water in Peptide Crystallization.
Guo, Mingxia; Rosbottom, Ian; Zhou, Lina; Yong, Chin W.; Zhou, Ling; Yin, Qiuxiang; Todorov, Ilian T.; Errington, Ethan; Heng, Jerry Y. Y.; The journal of physical chemistry letters 12 (2021) 8416–8422; doi:10.1021/acs.jpclett.1c01622

data_8000533
_publ_section_title
;
 Triglycine (GGG) Adopts a Polyproline II (pPII) Conformation in Its
 Hydrated Crystal Form: Revealing the Role of Water in Peptide
 Crystallization.
;
_journal_issue                   34
_journal_name_full               'The journal of physical chemistry letters'
_journal_page_first              8416
_journal_page_last               8422
_journal_paper_doi               10.1021/acs.jpclett.1c01622
_journal_volume                  12
_journal_year                    2021
_chemical_absolute_configuration unk
_chemical_formula_moiety         'C6 H11 N3 O4, 2(H2 O)'
_chemical_formula_sum            'C6 H15 N3 O6'
_chemical_formula_weight         225.21
_space_group_crystal_system      orthorhombic
_space_group_IT_number           29
_space_group_name_Hall           'P 2c -2ac'
_space_group_name_H-M_alt        'P c a 21'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     dual
_audit_creation_date             2020-11-25
_audit_creation_method
;
Olex2 1.2
(compiled 2017.01.04 svn.r3372 for OlexSys, GUI svn.r5292)
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   21.5256(8)
_cell_length_b                   9.7968(4)
_cell_length_c                   4.7685(2)
_cell_measurement_reflns_used    8940
_cell_measurement_temperature    113.15
_cell_measurement_theta_max      33.0820
_cell_measurement_theta_min      1.8750
_cell_volume                     1005.59(7)
_computing_cell_refinement       'CrysAlisPro 1.171.39.46 (Rigaku OD, 2018)'
_computing_data_collection       'CrysAlisPro 1.171.39.46 (Rigaku OD, 2018)'
_computing_data_reduction        'CrysAlisPro 1.171.39.46 (Rigaku OD, 2018)'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_computing_structure_solution    'ShelXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      113.15
_diffrn_detector                 'CCD plate'
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_details
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  t~exp~   \w     \q     \k     \f   Frames
--------------------------------------------------------------------------
  1  \w   -115.00  65.00   0.50    5.00    --  -25.00  45.00   0.00  360
  2  \w   -115.00  65.00   0.50    5.00    --  -25.00  45.00  90.00  360
  3  \w   -115.00  65.00   0.50    5.00    --  -25.00  45.00 180.00  360
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  'Rigaku Saturn 70'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0318095000
_diffrn_orient_matrix_UB_12      -0.0047427000
_diffrn_orient_matrix_UB_13      0.0375501000
_diffrn_orient_matrix_UB_21      -0.0017081000
_diffrn_orient_matrix_UB_22      0.0721711000
_diffrn_orient_matrix_UB_23      0.0086804000
_diffrn_orient_matrix_UB_31      -0.0084130000
_diffrn_orient_matrix_UB_32      0.0031238000
_diffrn_orient_matrix_UB_33      -0.1437052000
_diffrn_radiation_monochromator  confocal
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0521
_diffrn_reflns_av_unetI/netI     0.0335
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       29
_diffrn_reflns_limit_h_min       -29
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       6
_diffrn_reflns_limit_l_min       -6
_diffrn_reflns_number            12303
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.997
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.697
_diffrn_reflns_theta_min         1.892
_diffrn_source                   'rotating anode'
_diffrn_source_type              'Enhance (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.132
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.81712
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.488
_exptl_crystal_description       needle
_exptl_crystal_F_000             480
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.1
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.427
_refine_diff_density_min         -0.291
_refine_diff_density_rms         0.079
_refine_ls_abs_structure_details
;
 Flack x determined using 1012 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.5(6)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.041
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     172
_refine_ls_number_reflns         2602
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.041
_refine_ls_R_factor_all          0.0492
_refine_ls_R_factor_gt           0.0466
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1000P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1277
_refine_ls_wR_factor_ref         0.1305
_reflns_Friedel_coverage         0.782
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.993
_reflns_number_gt                2472
_reflns_number_total             2602
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jz1c01622_si_001.cif
_cod_data_source_block           r20201124b
_cod_database_code               8000533
_shelx_shelxl_version_number     2016/6
_chemical_oxdiff_formula         C6H15N3O5
_reflns_odcompleteness_completeness 99.94
_reflns_odcompleteness_iscentric 1
_reflns_odcompleteness_theta     28.64
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H,H) groups
2.a Secondary CH2 refined with riding coordinates:
 C2(H2A,H2B), C4(H4A,H4B), C6(H6A,H6B)
;
_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
- Detector area scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.818
_oxdiff_exptl_absorpt_empirical_full_min 0.637