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Showing 1 to 20 of 454 for “"Cofactor"”.
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Modeling dual-limitation kinetics incorporating intracellular cofactor responses
Intracellular cofactors--such as NADH, NAD, ATP, ADP, and P$\sb{\rm i}$--are important co-substrates that can affect the rate of the cell's catabolic and respiratory reactions. Pure-culture experiments with Pseudomonas putida P$\sb{\rm p}$F1 performed in a special chemostat apparatus, using acetate …
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Investigating cofactor transfer for a B₁₂-dependent enzyme
The metallocofactors utilized by enzymes can range in complexity from single metal ions to organometallic cofactors well over 1000 Da. These cofactors enable these metalloenzymes to accomplish a diverse set of unique and challenging chemistry that are critical to core life functions. One of these …
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Ultrafast Dynamics of Flavin Cofactor in Photolyase/Cryptochrome Family
… the photochemistry and photophysics of flavin cofactor. This dissertation presents a systematic investigation on the ultrafast dynamics of flavin cofactor in four redox states in photolyase/cryptochrome family proteins. In photolyase, the antenna molecule MTHF absorbs a photon and transfer the …
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Structural requirements for enzymatic efficiency in cofactor-independent decarboxylation
… (UMP), without the requirement of a cofactor. It provides catalytic rate enhancements of ~1017, compared to the uncatalyzed reaction, making it one of the most efficient enzymes known. OMPDC has thus been a paradigm to understand enzymatic catalysis. Yet, many aspects of its catalytic …
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Site-selective Labeling of the Nitrogenase Iron-Molybdenum Cofactor
… the chemistry that occurs at the catalytic cofactor of the Mo nitrogenase, the iron- molybdenum cofactor (FeMo-co), has been studied for decades. A challenge in understanding its unique reactivity is knowing how the valence electrons of FeMo-co are distributed and coupled, and how those …
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Proteomic Approaches For Profiling Cofactor-Dependent Proteins In Mycobacterium Tuberculosis
Tuberculosis is an infectious disease that currently affects a quarter of the world’s population. The rise of new antibacterial resistant strains makes the discovery and development of new antibiotics imperative. Chapter 1 provides a broad overview of PLP-dependent enzymes in Mycobacterium …
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Understanding the physiological role of cofactor F 420 in mycobacterium
The unique deazaflavin cofactor F420 occurs widely among mycobacterial species, including pathogenic ones. It is also involved in the activation of the antitubercular prodrug PA-824. We created a KO-mutant of F420 in M. bovis BCG to study the physiological significance of this cofactor in …
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Bacterial Cyanide Assimilation: Pterin Cofactor and Enzymatic Requirements for Substrate Oxidation
… a need for exogenously added pterin as a cofactor for the PpBCN3 enzyme system. However, results which showed that cells of PpBCN3 contained approximately seven times the amount of pterin as Pf11764 (of which a significant portion was protein-bound) were interpreted as indicating that …
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Crosstalk of TTC5 cofactor and the estrogen receptor in breast cancer
… X=any amino acid) motifs, interacts with cofactorssuch as TTC5 (tetratricopeptide repeat domain 5) which is a 440 amino acid protein,predicted to have 6 TPR (tetratricopeptide repeat) motifs and 4 LXXLL motifs, which areknown to mediate protein-protein interactions. TTC5 has been shown …
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Mechanistic Insights into MftR-Dependent Regulation of the Redox Cofactor Mycofactocin
<p>Organic redox cofactors are essential for life. While classic flavins and nicotinamides are widely distributed across all domains of life, nature has also evolved niche cofactors in subsets of life domains. For example, in <em>Actinobacteria</em>, coenzyme F420 is commonly used in place of …
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The Molybdenum Cofactor: Modeling the Swiss Army Knife of Metabolic Diversity
… designed to explore questions pertinent to Mo cofactor (Moco) enzymes. Structural and electronic differences between quinoxaline and pterin based models and how those differences affect reactivity studies are discussed, pterin reduction on models with, and without, the ability to form a pyran …
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The Role of The Androgen Receptor Cofactor P44/Wdr77 In Astrocyte Activation
<p>Astrogliosis is induced by neuronal damage and is also a pathological feature of the major aging-related neurodegenerative disorders. The mechanisms that control the cascade of astrogliosis have not been well established. In a previous study, we identified a novel androgen receptor …
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The design and synthesis of a novel thiamine cofactor for potential biocatalysis
… way of introducing these modifications is via a cofactor, due to their location within an enzyme’s active site. A number of crucial biochemical reactions in the cell require not only the enzymes for catalysis, but also the organic cofactors or metal ions. It is therefore advantageous to utilize …
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The Role of Phosphorylation in Modulating PC4 Function as a General Cofactor
… of basal transcription by the positive cofactor PC4 is alleviated by increasing amounts of TFIID, TFIIH and a preassembled RNA polymerase II holoenzyme complex but not by the other GTFs or RNA polymerase II. Our finding suggests that phosphorylation of PC4 by TFIID, TFIIH or RNA …
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Functional Consequences of Rna Exosome Complex Alteration By Conformational Changes and Cofactor Binding
… of the RNA exosome is partly determined by its cofactors that bind substrates. Rrp6 is a ribonuclease that interacts with the RNA exosome in the nucleus. It functions not only as a nuclease but also as an adaptor protein that bridges the RNA exosome to other cofactors such as an RNA helicase, …
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An old cofactor in a new light : how nature handles and repurposes adenosylcobalamin
… B 12) is a complex organometallic enzyme cofactor derived from vitamin B 12 that allows for challenging radical-based chemical transformations. Additionally, the biological role of AdoCbl was recently expanded by the discovery that AdoCbl can serve as a light sensor in light-dependent gene …
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Campylobacter jejuni Periplasmic Nitrate Reductase NapA as a Medium for Elucidating Molybdenum Cofactor Reactivity
… ligand within these enzymes is called molybdenum cofactor, or Moco. The structure of the enzyme is influential on reactivity of the molybdenum cofactor. The rate of catalysis, electron and proton transfer, and substrate preference can be affected by the amino acids surrounding Moco. Elucidating …
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Mechanism of biosynthesis of the dimanganese-tyrosyl radical cofactor of class lb Ribonucleotide reductase
… metal cluster. The diferric-Y (Fe" 2-Y·) cofactor of the class Ia RNRs self-assembles by reaction of Fe"2-NrdB with 02 and a reducing equivalent. Whether the class Ib RNRs utilize a diiron or dimanganese cofactor in vivo has been controversial. To determine the physiological …
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Synthetic Generation of an Azide-Bearing N-Mustard Cofactor Mimic of S-Adenosyl-L-Methionine
… of an azide-bearing <italic>N</italic>-mustard cofactor, 8-azido-5’-(diaminobutyric acid)-<italic>N</italic>-iodoethyl-5’-deoxyadenosine ammonium hydrochloride (<bold>2.1</bold>), has been accomplished with a small amount of impurity in several steps from commercially available …
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Building a Better Model for the Molybdenum Cofactor: A New Class of Molybdenum Dithiolene Complexes
<p>The molybdenum cofactor (Moco) is comprised of a molybdenum or tungsten center,at least one dithiolene chelate, and a tricyclic pyranopterin ligand. It is present in all living things, and it participates in global carbon, nitrogen, and sulfur cycles. The exact role the ligand plays in enzymatic …
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