title: Novel crystalline phase and first-order phase transitions of human insulin complexed with two distinct phenol derivatives.
abstract: The primary focus of the present work is the study of the effects that two ligands and the crystallization pH have on the crystalline forms of human insulin. For this purpose, human insulin (HI) was co-crystallized with two distinct phenolic derivatives: the organic ligands meta-cresol (m-cresol) and 4-nitrophenol. The formation of polycrystalline precipitates was then followed by means of structural characterization of the individual specimens in terms of unit-cell symmetry and parameters. In both cases, two different polymorphs were identified via X-ray powder diffraction measurements, the first of hexagonal symmetry (R3 space group) at higher pH values and the second of monoclinic symmetry (space group P21) with unit-cell parameters a = 87.4282 (5), b = 70.5020 (3), c = 48.3180 (4) Å, β = 106.8958 (4)°, the latter of which to our knowledge has never been observed before.
authors: Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, GR-26500 Patras, Greece.
authors: A
authors: A
authors: Valmas
authors: Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, GR-26500 Patras, Greece.
authors: K
authors: K
authors: Magiouf
authors: Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, GR-26500 Patras, Greece.
authors: S
authors: S
authors: Fili
authors: Diabetes Protein Engineering, Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Malov, Denmark.
authors: M
authors: M
authors: Norrman
authors: Diabetes Protein Engineering, Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Malov, Denmark.
authors: G
authors: G
authors: Schluckebier
authors: PANalytical B.V., Lelyweg 1, 7602 EA Almelo, The Netherlands.
authors: D
authors: D
authors: Beckers
authors: PANalytical B.V., Lelyweg 1, 7602 EA Almelo, The Netherlands.
authors: T
authors: T
authors: Degen
authors: European Synchrotron Radiation Facility, BP-220, F-38043 Grenoble CEDEX 9, France.
authors: J
authors: J
authors: Wright
authors: European Synchrotron Radiation Facility, BP-220, F-38043 Grenoble CEDEX 9, France.
authors: A
authors: A
authors: Fitch
authors: Excelsus Structural Solutions SPRL, Belgium.
authors: F
authors: F
authors: Gozzo
authors: Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, GR-26500 Patras, Greece.
authors: A E
authors: AE
authors: Giannopoulou
authors: Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, GR-26500 Patras, Greece.
authors: F
authors: F
authors: Karavassili
authors: Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, GR-26500 Patras, Greece.
authors: I
authors: I
authors: Margiolaki
mesh_terms: D003408:Cresols / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D006801:Humans; D061385:Insulins / Q000737:chemistry*; D008958:Models, Molecular; D009596:Nitrophenols / Q000737:chemistry*; D044367:Phase Transition; D033362:Powder Diffraction; D014961:X-Ray Diffraction
chemical_list: D003408:Cresols; D061385:Insulins; D009596:Nitrophenols; C042041:3-cresol; C024836:4-nitrophenol
keywords: human insulin; pH variation; powder diffraction