Toward an Alternative Intrinsic Probe for Spectroscopic Characterization of a Protein
| Autor: | Samir Kumar Pal, Nirmal Goswami, Abhinandan Makhal |
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| Přispěvatelé: | Goswami, Nirmal, Makhal, Abhinandan, Pal, Samir Kumar |
| Rok vydání: | 2010 |
| Předmět: |
Models
Molecular Circular dichroism Protein Conformation time-resolved fluoresence Electron Transport Residue (chemistry) Dynamic light scattering resonance energy transfer Fluorescence Resonance Energy Transfer Materials Chemistry Animals Humans tryptophan Physical and Theoretical Chemistry Kynurenine Fluorescent Dyes Chemistry Physical Chemistry Tryptophan Proteins Chemical modification 3-hydroxykynurenine dynamic light scattering Ligand (biochemistry) Fluorescence Surfaces Coatings and Films Transport protein human serum-albumin Spectrometry Fluorescence Biochemistry Biophysics Cattle nanoparticles |
| Zdroj: | The Journal of Physical Chemistry B. 114:15236-15243 |
| ISSN: | 1520-5207 1520-6106 |
| DOI: | 10.1021/jp105943d |
| Popis: | The intrinsic fluorescent amino acid tryptophan is the unanimous choice for the spectroscopic investigation of proteins. However, several complicacies in the interpretation of tryptophan fluorescence in a protein are inevitable and an alternative intrinsic protein probe is a longstanding demand. In this contribution, we report an electron-transfer reaction in a human transporter protein (HSA) cavity which causes the tryptophan residue (Trp214) to undergo chemical modification to form one of its metabolites kynurenine (Kyn214). Structural integrity upon modification of the native protein is confirmed by dynamic light scattering (DLS) as well as near and far 520circular dichroism (CD) spectroscopy. Femtosecond-resolved fluorescence transients of the modified protein describe the dynamics of solvent molecules in the protein cavity in both the native and denatured states. In order to establish general use of the probe, we have studied the dipolar interaction of Kyn214 with a surface-bound ligand (crystal violet, CV) of the protein. By using the sensitivity of FRET, we have determined the distance between Kyn214 (donor) and CV (acceptor). Our study is an attempt to explore an alternative intrinsic fluorescence probe for the spectroscopic investigation of a protein. In order to establish the efficacy of the modification technique we have converted the tryptophan residues of other proteins (bovine serum albumin, chymotrypsin and subtilisin Carlsberg) to kynurenine and confirmed their structural integrity. We have also shown that catalytic activity of the enzymes remains intact upon the modification. Refereed/Peer-reviewed |
| Databáze: | OpenAIRE |
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