Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.4 (RNase H)
 2,751 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dense, ultrathin networks of isocyanate terminated star-shaped poly(ethylene oxide) (PEO) molecules, cross-linked at their chain ends via urea groups, were shown to be extremely resistant to unspecific adsorption of proteins while at the same time suitable for easy biocompatible modification. Application by spin coating offers a simple procedure for the preparation of minimally interacting surfaces that are functionalized by suitable linker groups to immobilize proteins in their native conformations. These coatings form a versatile basis for biofunctional and biomimetic surfaces. We have demonstrated their advantageous properties by using single-molecule fluorescence microscopy to study immobilized proteins under destabilizing conditions. Biotinylated ribonuclease H (RNase H) was labeled with a fluorescence resonance energy transfer (FRET) pair of fluorescent dyes and attached to the surface by a biotin-streptavidin linkage. FRET analysis demonstrated completely reversible denaturation/renaturation behavior upon exposure of the surface-immobilized proteins to 6 M guanidinium chloride (GdmCl) followed by washing in buffer. A comparison with bovine serum albumin (BSA) coated surfaces and linear PEO brush surfaces yielded superior performance in terms of chemical stability, inertness and noninteracting nature of the star-polymer derived films.
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PMID:Biofunctionalized, ultrathin coatings of cross-linked star-shaped poly(ethylene oxide) allow reversible folding of immobilized proteins. 1505 12

Poly(ethylene oxide) (PEO) is known as an excellent coating material to minimize nonspecific protein adsorption. For an examination of biomolecules attached to surfaces with sensitivities down to the single-molecule level, demands on the surface additionally comprise low-intrinsic fluorescence of the coating material and a possibility to immobilize biomolecules in their functional conformation. One strategy that combines the protein-resistant properties of PEO with chemical functionality is the use of star-shaped PEOs that allow for interpolymer cross-linking. Our system consists of six-arm PEO-based star polymers functionalized with reactive isocyanate groups at the ends of the polymer chain. The isocyante groups allow intermolecular cross-linking so that high grafting densities may be achieved, which render the surfaces extremely resistant to protein adsorption. Application by spin coating offers a simple procedure for the preparation of minimally interacting surfaces. The reactive end groups may be further biofunctionalized to recognize specific biomolecules such as streptavidin or His-tagged proteins in specific geometries or as single isolated molecules. These properties, together with the advantageous chemical properties of PEO, render the surfaces ideal for immobilizing proteins with detection limits down to the single molecule level. This chapter focuses on the preparation of substrates that are suitable for single-molecule experiments. Besides a detailed description of surface preparation, two examples for the single-molecule detection of immobilized proteins, nucleosomes and RNase H, are presented that demonstrate the advantages of the star-polymer derived coatings over linear-grafted PEO.
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PMID:Star polymer surface passivation for single-molecule detection. 2058 Sep 56