TY  - JOUR
AU  - Rosenkranz, T.
AU  - Katranidis, A.
AU  - Atta, D.
AU  - Enderlein, J.
AU  - Gregor, I.
AU  - Grzelakowski, M.
AU  - Rigler, P.
AU  - Meier, W.
AU  - Fitter, J.
TI  - Observing Proteins as Single Molecules Encapsulated in Surface-Tethered Polymeric Nanocontainers
JO  - ChemBioChem
VL  - 10
SN  - 1439-4227
CY  - Weinheim
PB  - Wiley-VCH
M1  - PreJuSER-4647
SP  - 702 - 709
PY  - 2009
N1  - Jurgen Groll (SusTech GmbH & Co KG, Darmstadt) is greatly acknowledged for providing us with a protocol for cover slide coatings. We thank Iris v. d. Hocht for providing Atto655-labeled DOPE. T.R. acknowledges financial support by the International Helmholtz Research School on Biophysics and Soft Matter ("Bio-Soft'). J.F thanks G. Buldt (Forschungszentrum Julich) for continuous and sustainable support in his institute.
AB  - Immobilizing biomolecules provides the advantage of observing them individually for extended time periods, which is impossible to accomplish for freely diffusing molecules in solution. In order to immobilize individual protein molecules, we encapsulated them in polymeric vesicles made of amphiphilic triblock copolymers and tethered the vesicles to a cover slide surface. A major goal of this study is to investigate polymeric vesicles with respect to their suitability for protein-folding studies. The fact that polymeric vesicles possess an extreme stability under various chemical conditions is supported by our observation that harsh unfolding conditions do not perturb the structural integrity of the vesicles. Moreover, polymerosomes prove to be permeable to GdnHCl and, thereby, ideally suited for unfolding and refolding studies with encapsulated proteins. We demonstrate this with encapsulated phosphoglycerate kinase, which was fluorescently labeled with Atto655, a dye that exhibits pronounced photoinduced electron transfer (PET) to a nearby tryptophan residue in the native state. Under unfolding conditions, PET was reduced, and we monitored alternating unfolding and refolding conditions for individual encapsulated proteins.
KW  - Fluorescent Dyes: metabolism
KW  - Fungal Proteins: chemistry
KW  - Fungal Proteins: metabolism
KW  - Hydrophobic and Hydrophilic Interactions
KW  - Immobilized Proteins: chemistry
KW  - Immobilized Proteins: metabolism
KW  - Liposomes: chemistry
KW  - Nanoparticles: chemistry
KW  - Photochemical Processes
KW  - Polymers: chemistry
KW  - Protein Denaturation
KW  - Protein Folding
KW  - Protein Renaturation
KW  - Saccharomyces cerevisiae
KW  - Surface Properties
KW  - Fluorescent Dyes (NLM Chemicals)
KW  - Fungal Proteins (NLM Chemicals)
KW  - Immobilized Proteins (NLM Chemicals)
KW  - Liposomes (NLM Chemicals)
KW  - Polymers (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:19191249
UR  - <Go to ISI:>//WOS:000264168000015
DO  - DOI:10.1002/cbic.200800739
UR  - https://juser.fz-juelich.de/record/4647
ER  -