The Experts below are selected from a list of 102 Experts worldwide ranked by ideXlab platform
Sven Panke - One of the best experts on this subject based on the ideXlab platform.
-
The good of two worlds: increasing complexity in cell-free systems
Current Opinion in Biotechnology, 2013Co-Authors: Sonja Billerbeck, Johannes Härle, Sven PankeAbstract:In vitro biocatalytic systems have moved far beyond established uses in food, diagnostic, and chemical applications. As new strategies to construct and manage multiple enzymes in ever more complex systems are developed, novel applications emerge. In the field of chemistry, complex protein networks are applied to enable the production of fine chemicals, such as dihydroxyacetone phosphate, and even bulk chemicals, such as biofuels, from cheap sugars. Cell-free protein synthesis is applied to expanding protein and Nucleic Acid Biochemistry and enabling novel assay formats, while programmable DNA-circuits can be exploited to engineer sensitive detection methods. Novel developments in chemical analytics such as real-time mass spectrometry to follow the metabolism online, directed physical assembly of network members facilitating substrate channeling, and encapsulation forming biofunctional subunits enable a better control and potential for optimization.
-
The good of two worlds: Increasing complexity in cell-free systems
Current Opinion in Biotechnology, 2013Co-Authors: Sonja Billerbeck, Johannes Härle, Sven PankeAbstract:In vitro biocatalytic systems have moved far beyond established uses in food, diagnostic, and chemical applications. As new strategies to construct and manage multiple enzymes in ever more complex systems are developed, novel applications emerge. In the field of chemistry, complex protein networks are applied to enable the production of fine chemicals, such as dihydroxyacetone phosphate, and even bulk chemicals, such as biofuels, from cheap sugars. Cell-free protein synthesis is applied to expanding protein and Nucleic Acid Biochemistry and enabling novel assay formats, while programmable DNA-circuits can be exploited to engineer sensitive detection methods. Novel developments in chemical analytics such as real-time mass spectrometry to follow the metabolism online, directed physical assembly of network members facilitating substrate channeling, and encapsulation forming biofunctional subunits enable a better control and potential for optimization. © 2013 Elsevier Ltd.
J A Cowan - One of the best experts on this subject based on the ideXlab platform.
-
Encyclopedia of Catalysis - Magnesium Enzymes and Models
2002Co-Authors: J A CowanAbstract:Most enzymes used in Nucleic Acid Biochemistry, and many enzymes involved in general metabolism, require divalent magnesium as an essential activator. The selection of magnesium reflects the relatively high intracellular abundance of this ion, and its mechanism of action is tuned to the specific physicochemical properties that characterize its solution chemistry. In turn, this has required refinement of the protein environment to bind Mg2+ efficiently, and in a manner that preserves its catalytic integrity. This review summarizes what is known concerning the role of divalent magnesium as a mediator of enzymatic activity, and discusses this role in the context of the unique chemical properties of this metal cofactor. Mechanistic models and approaches that have been developed to understand these biological reactions are summarized, and a comparison is made with the catalytic mechanism demonstrated by metal complex mimics of magnesium-promoted reactions. Keywords: magnesium; mechanism; enzymes; nucleases; kinetics
-
metal ion stoichiometry of the hiv 1 rt ribonuclease h domain evidence for two mutually exclusive sites leads to new mechanistic insights on metal mediated hydrolysis in Nucleic Acid Biochemistry
Journal of Biological Inorganic Chemistry, 2000Co-Authors: J A Cowan, T Ohyama, K Howard, Jason W Rausch, S M Cowan, Le Grice SfAbstract:Crystallographic studies of the Mn2+-doped RNase H domain of human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT) [1] have revealed two bound Mn2+ separated by approximately 4 A and surrounded by a cluster of four conserved carboxylates. Escherichia coli RNase H is structurally similar to the RNase H domain of HIV-1 RT, but requires one divalent metal cation for its activity [2, 3], implying either that the HIV-1 RT RNase H domain contrasts in its ability to bind two divalent metal ions, or that the crystallographic data reflect specific use of Mn2+ and/or the doping technique employed. Metal binding stoichiometry has been determined for Mn2+ and the biologically more relevant Mg2+ cation by solution calorimetric studies of native and recombinant p66/p51 HIV-1 RT. Three Mn2+ ions bind to HIV-1 RT apo-enzyme: one at the DNA polymerase and two at the RNase H catalytic center, the latter being consistent with crystallographic results. However, only one Mg2+ ion is bound in the RNase H catalytic center. Several mechanistic implications arise from these results, including the possibility of mutually exclusive Mg2+ binding sites that might be occupied according to the specific reaction being catalyzed by the multifunctional RNase H domain. The occurrence of distinct binding stoichiometries for Mg2+ and Mn2+ to multifunctional enzymes has previously been reported [4].
-
transition metals as probes of metal cofactors in Nucleic Acid Biochemistry
Comments on Inorganic Chemistry, 1992Co-Authors: J A CowanAbstract:Abstract The alkali and alkaline earth metals (Na+, K+, Mg2+, Ca2+) are important regulators of Nucleic Acid Biochemistry; however, the kinetic, thermodynamic, and coordination details of their chemical interactions with polynucleotides and enzymes are not well characterized. Magnesium ion is an essential cofactor for many enzymes that digest, cut, ligate or alter the topology of DNA and RNA, or catalyze phosphoryl and nucleotidyl transfer reactions. In this article discussion is focussed on the role of magnesium as a cofactor for enzyme and ribozyme activity. Strategies employing transition metals as chemical probes of metallocofactor reactivity are critically assessed, and newer developments in the use of inert complexes to test the catalytically competent state of Mg2+(aq) are introduced.
Sonja Billerbeck - One of the best experts on this subject based on the ideXlab platform.
-
The good of two worlds: increasing complexity in cell-free systems
Current Opinion in Biotechnology, 2013Co-Authors: Sonja Billerbeck, Johannes Härle, Sven PankeAbstract:In vitro biocatalytic systems have moved far beyond established uses in food, diagnostic, and chemical applications. As new strategies to construct and manage multiple enzymes in ever more complex systems are developed, novel applications emerge. In the field of chemistry, complex protein networks are applied to enable the production of fine chemicals, such as dihydroxyacetone phosphate, and even bulk chemicals, such as biofuels, from cheap sugars. Cell-free protein synthesis is applied to expanding protein and Nucleic Acid Biochemistry and enabling novel assay formats, while programmable DNA-circuits can be exploited to engineer sensitive detection methods. Novel developments in chemical analytics such as real-time mass spectrometry to follow the metabolism online, directed physical assembly of network members facilitating substrate channeling, and encapsulation forming biofunctional subunits enable a better control and potential for optimization.
-
The good of two worlds: Increasing complexity in cell-free systems
Current Opinion in Biotechnology, 2013Co-Authors: Sonja Billerbeck, Johannes Härle, Sven PankeAbstract:In vitro biocatalytic systems have moved far beyond established uses in food, diagnostic, and chemical applications. As new strategies to construct and manage multiple enzymes in ever more complex systems are developed, novel applications emerge. In the field of chemistry, complex protein networks are applied to enable the production of fine chemicals, such as dihydroxyacetone phosphate, and even bulk chemicals, such as biofuels, from cheap sugars. Cell-free protein synthesis is applied to expanding protein and Nucleic Acid Biochemistry and enabling novel assay formats, while programmable DNA-circuits can be exploited to engineer sensitive detection methods. Novel developments in chemical analytics such as real-time mass spectrometry to follow the metabolism online, directed physical assembly of network members facilitating substrate channeling, and encapsulation forming biofunctional subunits enable a better control and potential for optimization. © 2013 Elsevier Ltd.
Le Grice Sf - One of the best experts on this subject based on the ideXlab platform.
-
metal ion stoichiometry of the hiv 1 rt ribonuclease h domain evidence for two mutually exclusive sites leads to new mechanistic insights on metal mediated hydrolysis in Nucleic Acid Biochemistry
Journal of Biological Inorganic Chemistry, 2000Co-Authors: J A Cowan, T Ohyama, K Howard, Jason W Rausch, S M Cowan, Le Grice SfAbstract:Crystallographic studies of the Mn2+-doped RNase H domain of human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT) [1] have revealed two bound Mn2+ separated by approximately 4 A and surrounded by a cluster of four conserved carboxylates. Escherichia coli RNase H is structurally similar to the RNase H domain of HIV-1 RT, but requires one divalent metal cation for its activity [2, 3], implying either that the HIV-1 RT RNase H domain contrasts in its ability to bind two divalent metal ions, or that the crystallographic data reflect specific use of Mn2+ and/or the doping technique employed. Metal binding stoichiometry has been determined for Mn2+ and the biologically more relevant Mg2+ cation by solution calorimetric studies of native and recombinant p66/p51 HIV-1 RT. Three Mn2+ ions bind to HIV-1 RT apo-enzyme: one at the DNA polymerase and two at the RNase H catalytic center, the latter being consistent with crystallographic results. However, only one Mg2+ ion is bound in the RNase H catalytic center. Several mechanistic implications arise from these results, including the possibility of mutually exclusive Mg2+ binding sites that might be occupied according to the specific reaction being catalyzed by the multifunctional RNase H domain. The occurrence of distinct binding stoichiometries for Mg2+ and Mn2+ to multifunctional enzymes has previously been reported [4].
F. Peter Guengerich - One of the best experts on this subject based on the ideXlab platform.
-
Thematic Minireview Series: Metals in Biology 2013
Journal of Biological Chemistry, 2013Co-Authors: F. Peter GuengerichAbstract:One-half of the available protein structures contain metals, explaining their roles as essential trace elements. Metals are also critical in many aspects of Nucleic Acid Biochemistry. This prologue briefly introduces the fifth of the Thematic Series on Metals in Biology, which began in the Journal of Biological Chemistry in 2009. The five minireviews in this 2013 series deal with the molybdenum prosthetic group (a pterin known as Moco); the biosynthesis of the “M-cluster” molybdenum prosthetic group of nitrogenase; the biosynthesis of the nickel-based metallocenter of the enzyme urease; several of the processing, transport, and medical aspects of cobalamins; and the growing roles of heme sensor proteins.
-
Thematic Minireview Series: Metals in Biology 2012
Journal of Biological Chemistry, 2012Co-Authors: F. Peter GuengerichAbstract:Metals are present in about one-half of the protein structures available and also have critical roles in Nucleic Acid Biochemistry. This prologue introduces the fourth of the Thematic Minireview Series on Metals in Biology, which deals with several topics involving iron, manganese, copper, and other metals. The six minireviews discuss metal transport and intracellular homeostasis, including chaperones and siderophores, maturation of the diiron active sites in hydrogenases, the balance between manganese and iron, and copper homeostasis relevant to pathogens.
