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Biomedical subjects

Günter Mayer

Publications and source records attributed to Günter Mayer.

11 recordsLinked to original sources
PubMed2006

Biologically active molecules with a "light switch".

Biologically active compounds which are light-responsive offer experimental possibilities which are otherwise very difficult to achieve. Since light can be manipulated very precisely, for example, with lasers and microscopes rapid jumps in concentration of the active form of molecules are possible with exact control of the area, time, and dosage. The development of such strategies started in the 1970s. This review summarizes new developments of the last five years and deals with "small molecules", proteins, and nucleic acids which can either be irreversibly activated with light (these compounds are referred to as "caged compounds") or reversibly switched between an active and an inactive state.

Animals↗
PubMed2005

Light regulation of aptamer activity: an anti-thrombin aptamer with caged thymidine nucleobases.

"Caged" derivatives of a 15 nucleotide ssDNA anti-thrombin aptamer have been synthesized in which thymidine nucleotides are modified with photolabile protecting groups. One caged thymidine in a key location is enough to completely mask the aptamer's function in respect to their affinity for thrombin and their inhibition of the blood clotting cascade. With light (366 nm) the caging group can be removed, yielding the unmodified active aptamer.

Antithrombins↗
PubMed2004

Sensing complex regulatory networks by conformationally controlled hairpin ribozymes.

The hairpin ribozyme catalyses RNA cleavage by a mechanism utilizing its conformational flexibility during the docking of two independently folded internal loop domains A and B. Based on this mechanism, we designed hairpin ribozyme variants that can be induced or repressed by external effector oligonucleotides influencing the docking process. We incorporated a third domain C to assimilate alternate stable RNA motifs such as a pseudo-half-knot or an internal stem-loop structure. Small sequence changes in domain C allowed targeted switching of ribozyme activity: the same effector oligonucleotide can either serve as an inducer or repressor. The ribozymes were applied to trp leader mRNA, the RNA sequence tightly bound by l-tryptophan-activated trp-RNA-binding attenuation protein (TRAP). When domain C is complementary to this mRNA, ribozyme activity can be altered by annealing trp leader mRNA, then specifically reverted by its TRAP/tryptophan-mediated sequestration. This approach allows to precisely sense the activity status of a protein controlled by its metabolite molecule.

Allosteric Regulation↗
PubMed2004

Aptamers in research and drug development.

Aptamers are short single-stranded oligonucleotides that fold into well defined three-dimensional shapes allowing them to bind to and inhibit their targets with high affinity and specificity. Aptamers can be considered truly multifunctional tools, because they can be generated rapidly and applied for specific detection, inhibition, and characterization of proteins. Recent publications impressively confirm that aptamers can be used either as surrogate inhibitors for the identification of small molecule lead compounds or as biopharmaceuticals.

Animals↗
PubMed2002

Development and characterization of temperature-controlled microreactors for protein crystallization.

Physico-chemical properties of the crystallization of biological macromolecules are of particular interest for an efficient way to get high-quality crystals. Concept and realization of a novel temperature-controlled microreactor to study these parameters is revealed. The characterization of the device is focussed on the temperature distribution across the reaction chamber, its long-term stability and accuracy as well as the regeneration of the surface inside the chamber after contamination with a hydrophilic protein (rGFP). We conclude that a microreactor for in situ observation of a temperature-controlled batch crystallization is in place.

Chemical Phenomena↗