Fabrice Balavoine

Helical Crystallization of Proteins on Carbon Nanotubes: A First Step towards the Development of New Biosensors**

have made them very promisingnanomaterials for new applications in chemistry and physics,particularly for the development of new nanotechnologies.However, few applications have so far been reported inbiology. Small proteins have been introduced into the insidehollow of opened nanotubes thus forming natural nano testtubes.

Specific interaction and two-dimensional crystallization of histidine tagged yeast RNA polymerase I on nickel-chelating lipids.

Nickel-chelating lipid monolayers were used to generate two-dimensional crystals from yeast RNA polymerase I that was histidine-tagged on one of its subunits. The interaction of the enzyme with the spread lipid layers was found to be imidazole dependent, and the formation of two-dimensional crystals required small amounts of imidazole, probably to select the specific interaction of the engineered tag with the nickel. Two distinct preparations of RNA polymerase I tagged on different subunits yielded two different crystal forms, indicating that the position of the tag determines the crystallization process. The orientation of the enzyme in both crystal forms is correlated with the location of the tagged subunits in a three-dimensional model which shows that the tagged subunits are in contact with the lipid layer.

Helicale Kristallisation von Proteinen auf Kohlenstoffnanoröhren: ein erster Schritt zur Entwicklung neuer Biosensoren

Zwei ganz unterschiedliche Proteine, Streptavidin und HupR, binden an mehrwandige Kohlenstoffnanorohren und bilden dort unter geeigneten Bedingungen regelmasige helicale Anordnungen (siehe Bild). Die Beschichtung der auseren Oberflache dieser Nanostrukturen mit biologischen Makromolekulen wurde mit Elektronenmikroskopie untersucht.

HIGHLY REGIOSELECTIVE PALLADIUM-CATALYZED CONDENSATION OF TERMINAL ACETYLENES WITH 2,5-DIIODOBENZOIC ACID

Abstract Palladium-catalyzed coupling reactions between terminal alkynes and 2,5-diiodobenzoic acid have been shown to be highly regioselective, giving a rapid and efficient route for the synthesis of disymmetric 2,5-bis ethynyl benzoic acid derivatives.

Specific interaction and two-dimensional crystal-lisation of histidine tagged yeast RNA polymerase I on Nickel-chelating lipids

Nickel-chelating lipid monolayers were used to generate two-dimensional crystals from yeast RNA polymerase I that was histidine-tagged on one of its subunits. The interaction of the enzyme with the spread lipid layers was found to be imidazole dependent, and the formation of two-dimensional crystals required small amounts of imidazole, probably to select the specific interaction of the engineered tag with the nickel. Two distinct preparations of RNA polymerase I tagged on different subunits yielded two different crystal forms, indicating that the position of the tag determines the crystallization process. The orientation of the enzyme in both crystal forms is correlated with the location of the tagged subunits in a three-dimensional model which shows that the tagged subunits are in contact with the lipid layer.