Structure Determination of an Oligopeptide Directly from Powder Diffraction Data

Tedesco, Emilio; Turner, Giles W.; Harris, Kenneth David Maclean; Johnston, Roy L.; Kariuki, Benson M.

doi:10.1002/1521-3773(20001215)39:24<4488::aid-anie4488>3.3.co;2-2

Cited by 22 publications

(23 citation statements)

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“…Significant methodological advances over the past decades transformed macromolecular XPD from an impossible task to a respectable method, circumventing the need for a suitable single crystal of the molecule of interest (Margiolaki & Wright, 2008;Karavassilia & Margiolaki, 2016). This approach has already been effectively employed for phase identification (Basso et al, 2005;Norrman et al, 2006;Collings et al, 2010;Papageorgiou et al, 2010;Karavassili et al, 2012;Valmas et al, 2015;Fili et al, 2015Fili et al, , 2016Trampari et al, 2018) as well as structure determination (Margiolaki et al, 2005(Margiolaki et al, , 2007(Margiolaki et al, , 2013Valmas et al, 2017) of a wide range of proteins and peptides (Tedesco et al, 2000(Tedesco et al, , 2001Cheung et al, 2002;Inouye & Kirschner, 2006;Fujii et al, 2011;Das et al, 2015) of pharmacological interest.…”

Section: Research Papersmentioning

confidence: 99%

Revisiting the structure of a synthetic somatostatin analogue for peptide drug design

Fili

Valmas

Spiliopoulou

et al. 2019

Acta Crystallogr B Struct Sci Cryst Eng Mater

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Natural or artificially manufactured peptides attract scientific interest worldwide owing to their wide array of pharmaceutical and biological activities. X-ray structural studies are used to provide a precise extraction of information, which can be used to enable a better understanding of the function and physicochemical characteristics of peptides. Although it is vulnerable to disassociation, one of the most vital human peptide hormones, somatostatin, plays a regulatory role in the endocrine system as well as in the release of numerous secondary hormones. This study reports the successful crystallization and complete structural model of octreotide, a stable octapeptide analogue of somatostatin. Common obstacles in crystallographic studies arising from the intrinsic difficulties of obtaining a suitable single-crystal specimen were efficiently overcome as polycrystalline material was employed for synchrotron and laboratory X-ray powder diffraction (XPD) measurements. Data collection and preliminary analysis led to the identification of unit-cell symmetry [orthorhombic, P2 1 2 1 2 1 , a = 18.5453 (15), b = 30.1766 (25), c = 39.798 (4) Å ], a process which was later followed by complete structure characterization and refinement, underlying the efficacy of the suggested (XPD) approach.

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Section: Research Papersmentioning

confidence: 99%

Revisiting the structure of a synthetic somatostatin analogue for peptide drug design

Fili

Valmas

Spiliopoulou

et al. 2019

Acta Crystallogr B Struct Sci Cryst Eng Mater

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“…As mentioned above, structure determination of polymorph A was performed directly from its powder X‐ray diffraction pattern. Recent developments in this field of research,8–10,12–14 particularly with regard to the structure solution stage of the structure determination process, have allowed considerable progress to be made in tackling structural problems when conventional single crystal X‐ray diffraction methods are not viable. The crystal structure of polymorph A was solved directly from the powder X‐ray diffraction data using the Genetic Algorithm (GA) technique, which is based on the principles of natural evolution, and works through a combination of mating, mutation, and natural selection procedures 15–17.…”

Section: Resultsmentioning

confidence: 99%

Polymorphism of a Novel Sodium Ion Channel Blocker

Cheung

Harris

Johnston

et al. 2003

Journal of Pharmaceutical Sciences

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“…The powder XRD patterns of L-lysine hemihydrate and L-lysine monohydrate were indexed using, respectively, the KOHL 23 and ITO 24 algorithms in the CRYSFIRE 25 Structure solution was carried out from the powder XRD data using the direct-space genetic algorithm (GA) technique [28][29][30][31][32] in the program EAGER. [33][34][35][36][37][38][39] In the structure-solution calculations, the L-lysine molecules were defined as zwitterions, with the amine group in the head group (rather than the amine group at the end of the side chain) assigned as the protonated base, as found in the crystal structure of anhydrous L-lysine. 1 In the structure-solution calculation for the hemihydrate, the L-lysine molecule (including hydrogen atoms) was defined by 10 structural variables: 2 positional variables (for space group C2, For both L-lysine hemihydrate and L-lysine monohydrate, 16 independent GA structuresolution calculations were carried out.…”

Section: Structure Determination From Powder Xrd Datamentioning

confidence: 99%

Understanding the Solid-State Hydration Behavior of a Common Amino Acid: Identification, Structural Characterization, and Hydration/Dehydration Processes of New Hydrate Phases of l-Lysine

et al. 2016

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The crystal structure of L-lysine was reported very recently and represented the final member of the set of 20 directly-encoded proteinogenic amino acids to have a crystal structure of the enantiomerically pure form determined. Under ambient conditions, L-lysine has a strong propensity to undergo hydration by incorporation of water into the crystal structure and dehydration under rigorously dry conditions is required to obtain anhydrous L-lysine. In the present paper, we explore the hydration of L-lysine, which has led to the identification and characterization of a hemihydrate phase and a monohydrate phase. As the hydration processes give rise to microcrystalline powder samples of the hydrate phases, powder X-ray diffraction has been exploited for crystal structure determination of both L-lysine hemihydrate and L-lysine monohydrate. The conditions for interconversion between anhydrous L-lysine and the two hydrate phases has been investigated by dynamic vapour sorption measurements, leading to an understanding of the hydration/dehydration behaviour in this system.

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Structure Determination of an Oligopeptide Directly from Powder Diffraction Data

Cited by 22 publications

References 1 publication

Revisiting the structure of a synthetic somatostatin analogue for peptide drug design

Revisiting the structure of a synthetic somatostatin analogue for peptide drug design

Polymorphism of a Novel Sodium Ion Channel Blocker

Understanding the Solid-State Hydration Behavior of a Common Amino Acid: Identification, Structural Characterization, and Hydration/Dehydration Processes of New Hydrate Phases of l-Lysine

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