A Glutathione-Based Hydrogel and Its Site-Selective Interactions with Water
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- 作者：Sumit S. Mahajan ; Rajan Paranji ; Ranjana Mehta ; Robert P. Lyon ; and William M. Atkins
- 刊名：Bioconjugate Chemistry
- 出版年：2005
- 出版时间：July 2005
- 年：2005
- 卷：16
- 期：4
- 页码：1019 - 1026
- 全文大小：354K
- 年卷期：v.16,no.4(July 2005)
- ISSN：1520-4812
文摘
Glutathione (
-glutamyl-cysteinyl-glycine; GSH) is ubiquitous biological tripeptide with multiplefunctions and possible therapeutic uses. The oxidized disulfide form (GSSG) self-assembles into fibrillaraggregates and gels in organic solvents, but not in solvent mixtures with high water content. Here,the disulfide bond has been replaced with a pyrenyl moiety in order to test the ability of GSH todirect noncovalent self-assembly in H2O, when combined with a hydrophobic driving force foraggregation. The resulting GSH-pyrene forms gels in 95% H2O:5% DMSO. The -glutamyl group iscritical for gelation, as it is with GSSG organo-gels, inasmuch as neither S-(pyrenyl)-cysteinyl-glycinenor the iodo-acetamido-pyrene precursor gels under any conditions studied. Circular dichroism andfluorescence spectroscopy indicate that the pyrene moieties cluster within the gels. Scanning andtransmission electron microscopy reveal fibrous networks with individual strands of ~50-100 nmdiameter. Saturation transfer difference (STD) NMR studies demonstrate that water interacts stronglywith GSH-borne protons in both solution and gel states, but only the gels include water-pyrenylinteractions with significant residence times.
-glutamyl-cysteinyl-glycine; GSH) is ubiquitous biological tripeptide with multiplefunctions and possible therapeutic uses. The oxidized disulfide form (GSSG) self-assembles into fibrillaraggregates and gels in organic solvents, but not in solvent mixtures with high water content. Here,the disulfide bond has been replaced with a pyrenyl moiety in order to test the ability of GSH todirect noncovalent self-assembly in H2O, when combined with a hydrophobic driving force foraggregation. The resulting GSH-pyrene forms gels in 95% H2O:5% DMSO. The -glutamyl group iscritical for gelation, as it is with GSSG organo-gels, inasmuch as neither S-(pyrenyl)-cysteinyl-glycinenor the iodo-acetamido-pyrene precursor gels under any conditions studied. Circular dichroism andfluorescence spectroscopy indicate that the pyrene moieties cluster within the gels. Scanning andtransmission electron microscopy reveal fibrous networks with individual strands of ~50-100 nmdiameter. Saturation transfer difference (STD) NMR studies demonstrate that water interacts stronglywith GSH-borne protons in both solution and gel states, but only the gels include water-pyrenylinteractions with significant residence times.