Structural studies of human insulin cocrystallized with phenol or resorcinol<i>via</i>powder diffraction

Karavassili, Fotini; Giannopoulou, A.; Kotsiliti, Eleni; Knight, Lisa; Norrman, Mathias; Schluckebier, G.; Drube, Lene; Fitch, Andrew N.; Wright, Jonathan P.; Margiolaki, I.

doi:10.1107/s0907444912039339

Cited by 25 publications

(53 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our previous studies on human insulin cocrystallized with phenol or resorcinol in a wide pH range have revealed several distinct polymorphic forms. In addition, a novel polymorph with monoclinic symmetry (P2 1 ) was identified for both kinds of ligands, displaying similar unit-cell parameters (Karavassili et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

High-resolution powder X-ray data reveal the T₆hexameric form of bovine insulin

Margiolaki

Giannopoulou

Wright

et al. 2013

Acta Crystallogr D Biol Crystallogr

Self Cite

View full text Add to dashboard Cite

A series of bovine insulin samples were obtained as 14 polycrystalline precipitates at room temperature in the pH range 5.0-7.6. High-resolution powder X-ray diffraction data were collected to reveal the T6 hexameric insulin form. Sample homogeneity and reproducibility were verified by additional synchrotron measurements using an area detector. Pawley analyses of the powder patterns displayed pH- and radiation-induced anisotropic lattice modifications. The pronounced anisotropic lattice variations observed for T6 insulin were exploited in a 14-data-set Rietveld refinement to obtain an average crystal structure over the pH range investigated. Only the protein atoms of the known structure with PDB code 2a3g were employed in our starting model. A novel approach for refining protein structures using powder diffraction data is presented. In this approach, each amino acid is represented by a flexible rigid body (FRB). The FRB model requires a significantly smaller number of refinable parameters and restraints than a fully free-atom refinement. A total of 1542 stereochemical restraints were imposed in order to refine the positions of 800 protein atoms, two Zn atoms and 44 water molecules in the asymmetric unit using experimental data in the resolution range 18.2-2.7 Å for all profiles.

show abstract

Section: Introductionmentioning

confidence: 99%

High-resolution powder X-ray data reveal the T₆hexameric form of bovine insulin

Margiolaki

Giannopoulou

Wright

et al. 2013

Acta Crystallogr D Biol Crystallogr

Self Cite

View full text Add to dashboard Cite

show abstract

“…(Figure 10). These crystalline polymorphs had been identified earlier by XRPD [29,56]. Diffraction profiles acquired for the P2 1(γ) polycrystalline samples extended to a resolution of~6.5 Å, whereas the lower resolution range for the P2 1(α) polycrystalline samples (~112-12 Å) was sufficient for successful indexing and Pawley analysis.…”

Section: Cocrystallization Of Hi With Phenolic Derivatives and Ph Depmentioning

confidence: 59%

“…Comparing to the isosymmetrical polymorph, P2 1(α) , identified by Karavassili et al in 2012 [29], which exhibited remarkably large cell dimensions concerning a and b axes (a = 114.0228 (8) (8) • ), the lattice parameters of this new polymorph P2 1(γ) are significantly shorter, approaching the already known range of dimensions that other known monoclinic cells adopt [22,28]. Between these two monoclinic forms and the already deposited in the Protein Data Bank P2 1(β) (PDB code: 1EV6; [28]), an unusual crystal packing for the P2 1(γ) polymorph is noteworthy.…”

Section: Cocrystallization Of Hi With Phenolic Derivatives and Ph Depmentioning

confidence: 84%

“…The volume of the cell while shifting from P2 1(γ) to P2 1(α) increases of about 6.5-fold resulting in a significant unit-cell modification. Summarizing these results in terms of cell volume, the P2 1(α) is one of the largest phases that has been identified to date through XRPD, while the C222 1 phase is being sorted as the second one (V (C2221) = 3.054.394 (63) Å 3 [55], V [P21(α)] = 1836620 (73) Å 3 [29]). Furthermore, from the crystallization of HI in the presence of 4-ethylresorcinol in the pH range~6.00-8.00 the crystals obtained, belonged to monoclinic symmetry (space group C2 (pH 5.93-6.25) and P2 1(β) (pH 6.73-8.05)).…”

Section: Cocrystallization Of Hi With Phenolic Derivatives and Ph Depmentioning

confidence: 99%

See 1 more Smart Citation

In Quest for Improved Drugs against Diabetes: The Added Value of X-ray Powder Diffraction Methods

Karavassili

Valmas

Fili

et al. 2017

Preprint

Self Cite

View full text Add to dashboard Cite

Human insulin (HI) is a well-characterized natural hormone which regulates glycose levels into the blood-stream and is widely used for diabetes treatment. Numerous studies have manifested that despite significant efforts devoted to structural characterization of this molecule and its complexes with organic compounds (ligands), there is still a rich diagram of phase transitions and novel crystalline forms to be discovered. Towards the improvement of drug delivery, identification of new insulin polymorphs from polycrystalline samples, simulating the commercially available drugs, is feasible today via macromolecular X-ray powder diffraction (XRPD). This approach has been developed, and is considered as a respectable method, which can be employed in biosciences for various purposes, such as observing phase transitions and characterizing bulk pharmaceuticals. An overview of the structural studies on human insulin complexes performed over the past decade employing both synchrotron and laboratory sources for XRPD measurements, is reported herein. This review aims to assemble all of the recent advances in the diabetes treatment field in terms of drug formulation, verifying in parallel the efficiency and applicability of protein XRPD for quick and accurate preliminary structural characterization in the large scale.

show abstract

“…in the database in order to narrow the searches in analogy with the search procedures in the PDB. When including experimental protein powder data sets a quality marker based on instrumental resolution would be useful: Well resolved synchrotron data is clearly preferred as they in some cases can be indexed and polymorph mixtures can be detected (Collings et al, 2010;Karavassili et al, 2012).…”

Section: Identification Based On Calculated Powder Patternsmentioning

confidence: 99%

Monitoring protein precipitates by in-house X-ray powder diffraction

et al. 2013

View full text Add to dashboard Cite

Powder diffraction from protein powders using in-house diffractometers is an effective tool for identification and monitoring of protein crystal forms and artifacts. As an alternative to conventional powder diffractometers a single crystal diffractometer equipped with an X-ray micro-source can be used to collect powder patterns from 1 μl samples. Using a small-angle Xray scattering (SAXS) camera it is possible to collect data within minutes. A streamlined program has been developed for the calculation of powder patterns from pdb-coordinates, and includes correction for bulk-solvent. A number of such calculated powder patterns from insulin and lysozyme have been included in the powder diffraction database and successfully used for search-match identification. However, the fit could be much improved if peak asymmetry and multiple bulk-solvent corrections were included. When including a large number of protein data sets in the database some problems can be foreseen due to the large number of overlapping peaks in the low-angle region, and small differences in unit cell parameters between pdb-data and powder data. It is suggested that protein entries are supplied with more searchable keywords as protein name, protein type, molecular weight, source organism etc. in order to limit possible hits. a)

show abstract

Structural studies of human insulin cocrystallized with phenol or resorcinolviapowder diffraction

Cited by 25 publications

References 38 publications

High-resolution powder X-ray data reveal the T₆hexameric form of bovine insulin

High-resolution powder X-ray data reveal the T₆hexameric form of bovine insulin

In Quest for Improved Drugs against Diabetes: The Added Value of X-ray Powder Diffraction Methods

Monitoring protein precipitates by in-house X-ray powder diffraction

Contact Info

Product

Resources

About

Structural studies of human insulin cocrystallized with phenol or resorcinolviapowder diffraction

Cited by 25 publications

References 38 publications

High-resolution powder X-ray data reveal the T6hexameric form of bovine insulin

High-resolution powder X-ray data reveal the T6hexameric form of bovine insulin

In Quest for Improved Drugs against Diabetes: The Added Value of X-ray Powder Diffraction Methods

Monitoring protein precipitates by in-house X-ray powder diffraction

Contact Info

Product

Resources

About

High-resolution powder X-ray data reveal the T₆hexameric form of bovine insulin

High-resolution powder X-ray data reveal the T₆hexameric form of bovine insulin