Aggregation of Poly(γ-benzylL-glutamate)s Followed by Time-Resolved Emission Anisotropy

Pokorná, Veronika; Výprachtický, Drahomı́r; Pecka, Jan

doi:10.1002/1616-5195(20010701)1:5<185::aid-mabi185>3.0.co;2-m

“…PBLG is known to form aggregates. [24] To further investigate the role of THF, PBLG‐based LLC phases in THF with biphenyl methanol‐ d 5 9 c as analyte were prepared. Temperature dependent 2 H NMR spectra clearly show a change of the quadrupolar splittings between 280 and 270 K, which is identical to the transition temperature T R already observed for PBPMLG phases investigated (see SI).…”

Section: Resultsmentioning

confidence: 99%

Investigations of the Alignment Process of PBPMLG: ²H NMR Analysis Reveals a Thermoresponsive 90° Flip of the Polymer

Schirra

¹

,

Hirschmann

²

,

Radulov

³

et al. 2021

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The application of anisotropic parameters in NMR‐spectroscopy enables the acquisition of spatial and angular information, complementary to those from conventional isotropic NMR‐measurements. The use of alignment media is a well‐established method for inducing anisotropy. PBPMLG is a recently discovered polyglutamate‐based alignment medium, exhibiting thermoresponsive behavior in the lyotropic liquid crystalline (LLC) phase, thus offering potential for deeper understanding of the alignment process. We present one approach for investigating the thermoresponsive behavior by synthesizing specifically deuterated PBPMLG‐isotopologues and their subsequent analyses using 2H NMR‐spectroscopy. It was possible to relate the observed thermoresponsive behavior to a flip of the polymer with respect to the external magnetic field—an effect never observed before in glutamate‐based polymeric alignment media. Furthermore, a solvent‐induced temperature dependent gelation was verified in THF, which might provide yet another opportunity to manipulate the properties of this alignment medium in the future.

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“…As fluorescence (FL) spectroscopy constitutes one of the most powerful tools to study the aggregation of polymers, traditional fluorescent probes such as carbazolyl, 17 dansyl, 18 and pyrene 19 have been chemically incorporated with poly(γbenzyl-L-glutamate) (PBLG) to monitor the chain conformations of PBLG in solution. For example, the absence of excimer emission in the pyrene-labeled poly(ethylene glycol)-b-PBLG 19 indicated that the pyrene groups were separated from each other in the self-assembled structure.…”

Section: ■ Introductionmentioning

confidence: 99%

Water-Soluble Poly(γ-propargyl-l-glutamate) Containing Pendant Sulfonate Ions and Terminal Fluorophore: Aggregation-Enhanced Emission and Secondary Structure

Shih

¹

,

Hsiao

²

,

Deng

³

et al. 2014

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Tetraphenylthiophene (TP) with aggregation-enhanced emission (AEE) property was used as terminal fluorophore of the water-soluble poly(γ-propargyl-l-glutamate) (PPLG)-based polymers of TP-iPPLGs to probe the relationship between the secondary structure (α-helix) of polypeptides and the AEE-related emission behavior. Intermolecular aggregation of the terminal TP unit in TP-iPPLG is sterically blocked by the large α-helical PPLG chains, leading to the weak AEE-related fluorescence in water. In contrast, the intermolecular approach between the terminal TP units of TP-iPPLG is accessible if TP was connected by peptide chin in random coil structure. Therefore, the helix-to-coil transition induced in the alkaline aqueous solution successfully enhances the emission intensity of the TP-iPPLG solution. The pH-induced conformation change in relationship to the AEE-related emission behavior is therefore evaluated in this study.

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“…PBLG is known to form aggregates [24] . To further investigate the role of THF, PBLG‐based LLC phases in THF with biphenyl methanol‐ d 5 9 c as analyte were prepared.…”

Section: Resultsmentioning

confidence: 99%

“…www.angewandte.de PBLG is known to form aggregates. [24] To further investigate the role of THF, PBLG-based LLC phases in THF with biphenyl methanol-d 5 9 c as analyte were prepared. Temperature dependent 2 H NMR spectra clearly show a change of the quadrupolar splittings between 280 and 270 K, which is identical to the transition temperature T R already observed for PBPMLG phases investigated (see SI).…”

Section: Angewandte Chemiementioning

confidence: 99%

Investigations of the Alignment Process of PBPMLG: ²H NMR Analysis Reveals a Thermoresponsive 90° Flip of the Polymer

Schirra

¹

,

Hirschmann

²

,

Radulov

³

et al. 2021

Angewandte Chemie

1

0

View full text Add to dashboard Cite

The application of anisotropic parameters in NMR‐spectroscopy enables the acquisition of spatial and angular information, complementary to those from conventional isotropic NMR‐measurements. The use of alignment media is a well‐established method for inducing anisotropy. PBPMLG is a recently discovered polyglutamate‐based alignment medium, exhibiting thermoresponsive behavior in the lyotropic liquid crystalline (LLC) phase, thus offering potential for deeper understanding of the alignment process. We present one approach for investigating the thermoresponsive behavior by synthesizing specifically deuterated PBPMLG‐isotopologues and their subsequent analyses using 2H NMR‐spectroscopy. It was possible to relate the observed thermoresponsive behavior to a flip of the polymer with respect to the external magnetic field—an effect never observed before in glutamate‐based polymeric alignment media. Furthermore, a solvent‐induced temperature dependent gelation was verified in THF, which might provide yet another opportunity to manipulate the properties of this alignment medium in the future.

show abstract

Aggregation of Poly(γ-benzylL-glutamate)s Followed by Time-Resolved Emission Anisotropy

Abstract: Time-resolved emission anisotropy, r(t), of PBLG-A in (a) DMF, (b) THF and (c) 1,4-dioxane at a concentration of 10.0 g N l -1 .

Cited by 8 publications

References 16 publications

Investigations of the Alignment Process of PBPMLG: ²H NMR Analysis Reveals a Thermoresponsive 90° Flip of the Polymer

Investigations of the Alignment Process of PBPMLG: ²H NMR Analysis Reveals a Thermoresponsive 90° Flip of the Polymer

Water-Soluble Poly(γ-propargyl-l-glutamate) Containing Pendant Sulfonate Ions and Terminal Fluorophore: Aggregation-Enhanced Emission and Secondary Structure

Investigations of the Alignment Process of PBPMLG: ²H NMR Analysis Reveals a Thermoresponsive 90° Flip of the Polymer

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Aggregation of Poly(γ-benzylL-glutamate)s Followed by Time-Resolved Emission Anisotropy

Abstract: Time-resolved emission anisotropy, r(t), of PBLG-A in (a) DMF, (b) THF and (c) 1,4-dioxane at a concentration of 10.0 g N l -1 .

Cited by 8 publications

References 16 publications

Investigations of the Alignment Process of PBPMLG: 2H NMR Analysis Reveals a Thermoresponsive 90° Flip of the Polymer

Investigations of the Alignment Process of PBPMLG: 2H NMR Analysis Reveals a Thermoresponsive 90° Flip of the Polymer

Water-Soluble Poly(γ-propargyl-l-glutamate) Containing Pendant Sulfonate Ions and Terminal Fluorophore: Aggregation-Enhanced Emission and Secondary Structure

Investigations of the Alignment Process of PBPMLG: 2H NMR Analysis Reveals a Thermoresponsive 90° Flip of the Polymer

Contact Info

Product

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Investigations of the Alignment Process of PBPMLG: ²H NMR Analysis Reveals a Thermoresponsive 90° Flip of the Polymer

Investigations of the Alignment Process of PBPMLG: ²H NMR Analysis Reveals a Thermoresponsive 90° Flip of the Polymer

Investigations of the Alignment Process of PBPMLG: ²H NMR Analysis Reveals a Thermoresponsive 90° Flip of the Polymer