Secondary Structure and Pd(II) Coordination in S-Layer Proteins from Bacillus sphaericus Studied by Infrared and X-Ray Absorption Spectroscopy

Fahmy, Karim; Merroun, Mohamed L.; Pollmann, Katrin; Raff, Johannes; Savchuk, Olesya; Hennig, Christoph; Selenska‐Pobell, Sonja

doi:10.1529/biophysj.105.079137

Cited by 72 publications

(81 citation statements)

References 55 publications

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“…[32][33][34] It can be seen from (Fig. SI-4), the first (Ni-O) peak at R 2.03~2.04 Å remains relatively constant in amplitude with increasing temperature.…”

mentioning

confidence: 91%

Sorption Speciation of Nickel(ii) onto Ca-Montmorillonite: Batch, EXAFS Techniques and Modeling

Tan

Montavon

et al. 2011

Dalton Trans.

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The sorption speciation of Ni(II) on Ca-montmorillonite was evaluated using a combination of batch experiments, extended X-ray absorption fine structure (EXAFS) spectroscopy and modeling. The pH and temperature at the aqueous-montmorillonite interface affects both the extent of Ni(II) sorption as well as the local atomic structure of the adsorbed Ni(II) ions. At 0.001 mol/L Ca(NO 3 ) 2 and low pH, the study reveals that the majority of Ni(II) is adsorbed in the interlayers of Ca-montmorillonite coordinated by six water molecules in an octahedron as an outer-sphere complex. At higher pH, inner-sphere surface complexes are formed. The Ni-Si/Al distances (R Ni-Al =3.00 Å, R Ni-Si1 =3.10 Å and R Ni-Si2 =3.26 Å) determined by EXAFS confirm the formation of mononuclear complexes located at the edges of Ca-montmorillonite platelets at pH 7.5 and 8.5. At pH 10.0, the Ni-Ni/Si distances (R Ni-Ni =3.07 Å and R Ni-Si =3.26Å) indicates the formation of Ni-phyllosilicate precipitates. A rise in temperature promotes inner-sphere complexation, which in turn leads to an increase in Ni(II) sorption on Ca-montmorillonite.Sorption edges are fitted excellently by surface complexation model (SCM) with the aid of surface species determined from EXAFS spectroscopy.

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“…[32][33][34] It can be seen from (Fig. SI-4), the first (Ni-O) peak at R 2.03~2.04 Å remains relatively constant in amplitude with increasing temperature.…”

mentioning

confidence: 91%

Sorption Speciation of Nickel(ii) onto Ca-Montmorillonite: Batch, EXAFS Techniques and Modeling

Tan

Montavon

et al. 2011

Dalton Trans.

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“…The FTIR spectra verified the conjugation between the polymer and cisplatin, as indicated in Figure 11. The spectra also exhibited two pronounced peaks at 3292 and 1385 cm -1 , revealing the absorptions of N-H stretching from cisplatin ligands (Pt-NH 2 ), and the chelation of the COO-Pt stretch, respectively [47,48]. In addition, a reduction in absorbance of the carbonyl (C=O) stretch of COOH at 1704 cm -1 relative to the amide C=O band at 1633 cm -1 (the difference between relative intensity in (a) and (b) in Figure 11) is consistent with the prediction that some of the -COOH groups would react with the Pt atoms in a ligand exchange reaction [49].…”

Section: Preparation Of the Cisplatin-loadedmentioning

confidence: 99%

Microwave-assisted synthesis of thermo- and pH-responsive antitumor drug carrier through reversible addition–fragmentation chain transfer polymerization

Wang¹,

Zheng²,

Chang³

et al. 2017

Express Polym. Lett.

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Abstract. This paper reports the rapid synthesis of a dual-responsive copolymer through reversible addition-fragmentation chain transfer (RAFT) polymerization under microwave irradiation. Through use of 2-ethoxycarbonothioylthio acetic acid (ECTA) as a RAFT agent, the microwave-assisted polymerization rate of N-isopropylacrylamide (NIPAM) was approximately 150 times faster than that observed under conventional heating conditions, and the resulting homopolymer can be reactivated as a macroinitiator to produce poly(N-isopropylacrylamide-block-methacrylic acid) (PNIPAM-b-PMAA) block copolymers through a similar method. Research into the detailed polymerization kinetics of the PNIPAM and PNIPAM-b-PMAA revealed living characteristics that included a linear relationship between M n and conversion, controlled molecular weights, and a relatively narrow molecular weight distribution. The solution of the block copolymers in phosphate-buffered saline buffer displayed a phase transition at a lower critical solution temperature transition of 42°C, and altering the pH from 7 to 3.5 resulted in various degrees of polymer aggregation in the solution. Cisplatin was loaded to the polymeric carrier through a ligand exchange to form a macromolecular prodrug. The observed critical micelle concentration was 0.25 mg/mL. Overall, these polymers offer considerable potential for developing a new multifunctional drug delivery system.

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“…This interaction may also be used as the initial steps to form nanoclusters [42][43][44] [48,49]. In addition, it is now known that bacteria use horizontal genetic transfer of S-layer encoding genes to propagate their capacity to bind uranium [50].…”

Section: Fig 3 Interaction Of Metals and Cells Wearing S-layersmentioning

confidence: 99%

Biophysical Methods for the Elucidation of the S-Layer Proteins/Metal Interaction

Mobili

2013

IJBCRR

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Surface-layers (S-layers) are macromolecular paracrystalline arrays of proteins or glycoproteins that can self-assemble into 2-dimensional semi-permeable meshworks to overlay the cell surface of many bacteria and archaea. They usually assemble into lattices with oblique, square or hexagonal symmetry and serve as an interface between the bacterial cell and the environment. Isolated S-layers can recrystallize into two-dimensional regular arrays in suspension or on various surfaces, thus being an appropriate material for several bionanotechnological purposes. Promising applications of S-layers include their use as biotemplates for the capture of metal ions or the synthesis of metal nanoclusters. Research ArticleInternational Journal of Biochemistry Research & Review, 3(1): 39-62, 2013 40 Considering the use of S-layers as biotemplates for the organization of metal ions or metallic nanoclusters, research on potential of surface layer proteins (SLP) and metals can be understood as an interdisciplinary field, in which different biophysical techniques supply complementary information. In this review, we discuss the SLP as native or engineered "bottom-up" building blocks for metal immobilization structures. We also describe the biophysical techniques used to analyze metal binding properties as well as the information obtained from the investigation of these structures.

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Secondary Structure and Pd(II) Coordination in S-Layer Proteins from Bacillus sphaericus Studied by Infrared and X-Ray Absorption Spectroscopy

Cited by 72 publications

References 55 publications

Sorption Speciation of Nickel(ii) onto Ca-Montmorillonite: Batch, EXAFS Techniques and Modeling

Sorption Speciation of Nickel(ii) onto Ca-Montmorillonite: Batch, EXAFS Techniques and Modeling

Microwave-assisted synthesis of thermo- and pH-responsive antitumor drug carrier through reversible addition–fragmentation chain transfer polymerization

Biophysical Methods for the Elucidation of the S-Layer Proteins/Metal Interaction

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