Probing the interior of peptide amphiphile supramolecular aggregates

John D. Tovar, Randal C. Claussen, Samuel I Stupp

Research output: Contribution to journalArticle

81 Citations (Scopus)

Abstract

We present a study of the aqueous solvation within self-assembled structures formed from peptide amphiphiles. We have placed tryptophan and pyrene chromophores onto the peptide backbone to enable spectroscopic examinations of the interior of the resulting supramolecular objects. Self-assembly constrains the chromophores to a defined location within an aggregate, and they experience differing degrees of quencher penetration reflective of their depth within the nanostructure. Tryptophan fluorescence indicates that the interiors remain well-solvated, suggesting that the supramolecular aggregates maintain high degrees of free volume. The Stern-Volmer quenching constants and the fractional accessibility (of covalently bound pyrene) progressively increase as the chromophore is placed closer to the aggregate exterior. Furthermore, these aggregates encourage chromophore uptake from aqueous solution as evidenced by the solubilization of free pyrene chromophores. Our findings demonstrate that covalently bound fluorophores within an aggregate can interact with the external environment. Studies with small molecular probes indicate that these self-assembled architectures may represent viable vehicles to sequester hydrophobic, insoluble organic molecules (within the interior) and to present signaling protein epitopes to cells (on the periphery).

Original languageEnglish
Pages (from-to)7337-7345
Number of pages9
JournalJournal of the American Chemical Society
Volume127
Issue number20
DOIs
Publication statusPublished - May 25 2005

Fingerprint

Amphiphiles
Chromophores
Peptides
Pyrene
Tryptophan
Molecular Probes
Nanostructures
Epitopes
Fluorescence
Fluorophores
Free volume
Solvation
Self assembly
Quenching
pyrene
Proteins
Molecules

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Probing the interior of peptide amphiphile supramolecular aggregates. / Tovar, John D.; Claussen, Randal C.; Stupp, Samuel I.

In: Journal of the American Chemical Society, Vol. 127, No. 20, 25.05.2005, p. 7337-7345.

Research output: Contribution to journalArticle

Tovar, John D. ; Claussen, Randal C. ; Stupp, Samuel I. / Probing the interior of peptide amphiphile supramolecular aggregates. In: Journal of the American Chemical Society. 2005 ; Vol. 127, No. 20. pp. 7337-7345.
@article{495822b6b69a46fda92002f9a38ad83a,
title = "Probing the interior of peptide amphiphile supramolecular aggregates",
abstract = "We present a study of the aqueous solvation within self-assembled structures formed from peptide amphiphiles. We have placed tryptophan and pyrene chromophores onto the peptide backbone to enable spectroscopic examinations of the interior of the resulting supramolecular objects. Self-assembly constrains the chromophores to a defined location within an aggregate, and they experience differing degrees of quencher penetration reflective of their depth within the nanostructure. Tryptophan fluorescence indicates that the interiors remain well-solvated, suggesting that the supramolecular aggregates maintain high degrees of free volume. The Stern-Volmer quenching constants and the fractional accessibility (of covalently bound pyrene) progressively increase as the chromophore is placed closer to the aggregate exterior. Furthermore, these aggregates encourage chromophore uptake from aqueous solution as evidenced by the solubilization of free pyrene chromophores. Our findings demonstrate that covalently bound fluorophores within an aggregate can interact with the external environment. Studies with small molecular probes indicate that these self-assembled architectures may represent viable vehicles to sequester hydrophobic, insoluble organic molecules (within the interior) and to present signaling protein epitopes to cells (on the periphery).",
author = "Tovar, {John D.} and Claussen, {Randal C.} and Stupp, {Samuel I}",
year = "2005",
month = "5",
day = "25",
doi = "10.1021/ja043764d",
language = "English",
volume = "127",
pages = "7337--7345",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "20",

}

TY - JOUR

T1 - Probing the interior of peptide amphiphile supramolecular aggregates

AU - Tovar, John D.

AU - Claussen, Randal C.

AU - Stupp, Samuel I

PY - 2005/5/25

Y1 - 2005/5/25

N2 - We present a study of the aqueous solvation within self-assembled structures formed from peptide amphiphiles. We have placed tryptophan and pyrene chromophores onto the peptide backbone to enable spectroscopic examinations of the interior of the resulting supramolecular objects. Self-assembly constrains the chromophores to a defined location within an aggregate, and they experience differing degrees of quencher penetration reflective of their depth within the nanostructure. Tryptophan fluorescence indicates that the interiors remain well-solvated, suggesting that the supramolecular aggregates maintain high degrees of free volume. The Stern-Volmer quenching constants and the fractional accessibility (of covalently bound pyrene) progressively increase as the chromophore is placed closer to the aggregate exterior. Furthermore, these aggregates encourage chromophore uptake from aqueous solution as evidenced by the solubilization of free pyrene chromophores. Our findings demonstrate that covalently bound fluorophores within an aggregate can interact with the external environment. Studies with small molecular probes indicate that these self-assembled architectures may represent viable vehicles to sequester hydrophobic, insoluble organic molecules (within the interior) and to present signaling protein epitopes to cells (on the periphery).

AB - We present a study of the aqueous solvation within self-assembled structures formed from peptide amphiphiles. We have placed tryptophan and pyrene chromophores onto the peptide backbone to enable spectroscopic examinations of the interior of the resulting supramolecular objects. Self-assembly constrains the chromophores to a defined location within an aggregate, and they experience differing degrees of quencher penetration reflective of their depth within the nanostructure. Tryptophan fluorescence indicates that the interiors remain well-solvated, suggesting that the supramolecular aggregates maintain high degrees of free volume. The Stern-Volmer quenching constants and the fractional accessibility (of covalently bound pyrene) progressively increase as the chromophore is placed closer to the aggregate exterior. Furthermore, these aggregates encourage chromophore uptake from aqueous solution as evidenced by the solubilization of free pyrene chromophores. Our findings demonstrate that covalently bound fluorophores within an aggregate can interact with the external environment. Studies with small molecular probes indicate that these self-assembled architectures may represent viable vehicles to sequester hydrophobic, insoluble organic molecules (within the interior) and to present signaling protein epitopes to cells (on the periphery).

UR - http://www.scopus.com/inward/record.url?scp=19944414362&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=19944414362&partnerID=8YFLogxK

U2 - 10.1021/ja043764d

DO - 10.1021/ja043764d

M3 - Article

C2 - 15898782

AN - SCOPUS:19944414362

VL - 127

SP - 7337

EP - 7345

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 20

ER -