Instructions for use Title ENZYMOLOGICAL STUDIES ON
... model system of glycolysis in the study of the role of enzymes in homeostasis, key differences between the enzymatic steps of glycolysis and those of gluconeogenesis have been delaed with by many investigators. The extensive investigations regarding this showed that dietary, hormonal and pathologica ...
... model system of glycolysis in the study of the role of enzymes in homeostasis, key differences between the enzymatic steps of glycolysis and those of gluconeogenesis have been delaed with by many investigators. The extensive investigations regarding this showed that dietary, hormonal and pathologica ...
Hydrolysisof Glutathioneby Human Liver `y
... techniques involved. Unfortunately, use of such unphysiological substrates has not been very helpful in the study of the physiological role of ‘y-glutamyltransferase. The pH optima with these substrates is 8.25 (9, 14) and initial velocity rates are maximal only with high concentrations of the dipep ...
... techniques involved. Unfortunately, use of such unphysiological substrates has not been very helpful in the study of the physiological role of ‘y-glutamyltransferase. The pH optima with these substrates is 8.25 (9, 14) and initial velocity rates are maximal only with high concentrations of the dipep ...
The Metabolism of Acetate by the Blue-green Algae
... in the presence of sodium acetate and absence of carbon dioxide were unsuccessful. The failure of acetate and other substrates to stimulate respiration in blue-green algae has been known for some time (Kratz & Myers, 1955b)and in our experiments A . variabilis was no exception. Over a range of p H v ...
... in the presence of sodium acetate and absence of carbon dioxide were unsuccessful. The failure of acetate and other substrates to stimulate respiration in blue-green algae has been known for some time (Kratz & Myers, 1955b)and in our experiments A . variabilis was no exception. Over a range of p H v ...
Structural and mechanistic studies of enolase George H Reed
... with respect to the stereochemistry of substrate binding, and the coordination schemes of both essential magnesium ions was clear. Figure 5 shows the active site with bound 2-PGA and the residues that are in position to participate in catalysis. An intricate coordination of the magnesium ions to the ...
... with respect to the stereochemistry of substrate binding, and the coordination schemes of both essential magnesium ions was clear. Figure 5 shows the active site with bound 2-PGA and the residues that are in position to participate in catalysis. An intricate coordination of the magnesium ions to the ...
Activation by Exercise of Human Skeletal Muscle Pyruvate
... The ratio of active to total pyruvate dehydrogenase activity found in the present study in human resting vastus lateralis muscle is higher than previously found in rat muscle [81. Studies in our laboratory, with methods similar to those used in the present work [131, showed total pyruvate dehydrogen ...
... The ratio of active to total pyruvate dehydrogenase activity found in the present study in human resting vastus lateralis muscle is higher than previously found in rat muscle [81. Studies in our laboratory, with methods similar to those used in the present work [131, showed total pyruvate dehydrogen ...
Phylogenomic Investigation of Phospholipid Synthesis in Archaea
... more ancient because they were known to provide isoprenoids for several pathways while bacteria and eukaryotes were thought to have more specialized enzymes. Later phylogenetic analyses with more sequences showed two groups corresponding to the functional split between short and long-chain enzymes [ ...
... more ancient because they were known to provide isoprenoids for several pathways while bacteria and eukaryotes were thought to have more specialized enzymes. Later phylogenetic analyses with more sequences showed two groups corresponding to the functional split between short and long-chain enzymes [ ...
Principles of Metabolic Regulation
... Under resting conditions, [ATP] is high and [AMP] low because the total adenine nucleotide pool is constant. [Citrate] and [acetyl-CoA] are intermediate because O2 is not limiting and the citric acid cycle is functioning. Under conditions of active exertion (running), O2 becomes limiting and ATP syn ...
... Under resting conditions, [ATP] is high and [AMP] low because the total adenine nucleotide pool is constant. [Citrate] and [acetyl-CoA] are intermediate because O2 is not limiting and the citric acid cycle is functioning. Under conditions of active exertion (running), O2 becomes limiting and ATP syn ...
Review Article Hydroxyl radical generation theory: a possible
... Kirkman and Gaetani [3] in their review proposed schemes for reducing various states of catalase using intermediate model with and without NADPH. The radicals of amino acids within the structure of catalase were accounted specific for the reduction of compound-I to form different intermediates. Thes ...
... Kirkman and Gaetani [3] in their review proposed schemes for reducing various states of catalase using intermediate model with and without NADPH. The radicals of amino acids within the structure of catalase were accounted specific for the reduction of compound-I to form different intermediates. Thes ...
BIOSYNTHESIS OF AMINO ACIDS, NUCLEOTIDES, AND
... conserved complex of proteins called the nitrogenase complex (Fig. 22–2), the crucial components of which are dinitrogenase reductase and dinitrogenase (Fig. 22–3). Dinitrogenase reductase (Mr 60,000) is a dimer of two identical subunits. It contains a single 4Fe4S redox center (see Fig. 19–5), boun ...
... conserved complex of proteins called the nitrogenase complex (Fig. 22–2), the crucial components of which are dinitrogenase reductase and dinitrogenase (Fig. 22–3). Dinitrogenase reductase (Mr 60,000) is a dimer of two identical subunits. It contains a single 4Fe4S redox center (see Fig. 19–5), boun ...
06_Metabolism of lipid
... • FA synthesis and degradation occur by two completely separate pathways • When glucose is plentiful, large amounts of acetyl CoA are produced by glycolysis and can be used for fatty acid synthesis ...
... • FA synthesis and degradation occur by two completely separate pathways • When glucose is plentiful, large amounts of acetyl CoA are produced by glycolysis and can be used for fatty acid synthesis ...
A Biosensor Based on Immobilization of Horseradish Peroxidase in Chitosan Matrix Cross-linked with Glyoxal for Amperometric Determination of Hydrogen Peroxide
... while little use of glyoxal can be found in this area. The present work was attempt to develop a simple and robust amperometric hydrogen peroxide biosensor based on HRP immobilized by chitosan film cross-linked with glyoxal. We selected the “sandwich” configuration: ferrocene-chitosan: HRP: chitosan ...
... while little use of glyoxal can be found in this area. The present work was attempt to develop a simple and robust amperometric hydrogen peroxide biosensor based on HRP immobilized by chitosan film cross-linked with glyoxal. We selected the “sandwich” configuration: ferrocene-chitosan: HRP: chitosan ...
CALPAIN: TRANSITIONING FROM THE USE OF THE
... Figure 1.4. Domain structure of CAST and its interaction with calpain........................................ 16 Figure 2.1. Inactive m-calpain (mC105S) hydrolysis activity assay of mini-calpains 1 (A), 8 (B), 3 (C), 9 (D) and 15 (E)................................................................... ...
... Figure 1.4. Domain structure of CAST and its interaction with calpain........................................ 16 Figure 2.1. Inactive m-calpain (mC105S) hydrolysis activity assay of mini-calpains 1 (A), 8 (B), 3 (C), 9 (D) and 15 (E)................................................................... ...
Life in the slow lane: molecular mechanisms of estivation
... controls that decrease substrate oxidation and ATP production (rather than those that decrease ATP use) in the development and regulation of the hypometabolic state. Factors contributing to intrinsic metabolic rate depression include suppressed rates of fuel catabolism, ion channel arrest, and reduc ...
... controls that decrease substrate oxidation and ATP production (rather than those that decrease ATP use) in the development and regulation of the hypometabolic state. Factors contributing to intrinsic metabolic rate depression include suppressed rates of fuel catabolism, ion channel arrest, and reduc ...
Metabolic significance of inorganic triphosphate, thiamine
... responsible for this activity. We showed that the E. coli CYTH enzyme, ygiF, although highly specific for PPPi plays only a minor role in the cytosolic PPPase activity, while most of the activity is due to inorganic pyrophosphatase. In animal tissues, most PPPase activity is due to the short-chain e ...
... responsible for this activity. We showed that the E. coli CYTH enzyme, ygiF, although highly specific for PPPi plays only a minor role in the cytosolic PPPase activity, while most of the activity is due to inorganic pyrophosphatase. In animal tissues, most PPPase activity is due to the short-chain e ...
The enzymes of biotin dependent CO2 metabolism: What structures
... third component, the biotin carboxyl carrier protein (BCCP), contains the covalently attached biotin cofactor. BCCP functions as a ‘‘swinging arm’’ that allows the cofactor to shuttle between the biotin carboxylase and carboxyltransferase subunits of the complex. The structure of biotin carboxylase ...
... third component, the biotin carboxyl carrier protein (BCCP), contains the covalently attached biotin cofactor. BCCP functions as a ‘‘swinging arm’’ that allows the cofactor to shuttle between the biotin carboxylase and carboxyltransferase subunits of the complex. The structure of biotin carboxylase ...
Catalytic mechanism of nucleoside diphosphate kinase investigated
... to eight substrate concentrations. kcat was derived by varying both ATP and NDP concentrations while keeping the [ATP]/ [NTP] ratio fixed to 4.0 for TDP and 0.1-0.2 for the poorer substrates (27, 28). Substrate inhibition introduces a small systematic error under these conditions (28), and no correc ...
... to eight substrate concentrations. kcat was derived by varying both ATP and NDP concentrations while keeping the [ATP]/ [NTP] ratio fixed to 4.0 for TDP and 0.1-0.2 for the poorer substrates (27, 28). Substrate inhibition introduces a small systematic error under these conditions (28), and no correc ...
Oxidation and biosynthesis of fatty acids
... Insulin stimulates fatty acid synthesis causing dephosphorylation of carboxylase. Glucagon and epinephrine have the reverse effect (keep the carboxylase in the inactive phosphorylated state). Protein kinase is activated by AMP and inhibited by ATP. Carboxylase is inactivated when the energy charge i ...
... Insulin stimulates fatty acid synthesis causing dephosphorylation of carboxylase. Glucagon and epinephrine have the reverse effect (keep the carboxylase in the inactive phosphorylated state). Protein kinase is activated by AMP and inhibited by ATP. Carboxylase is inactivated when the energy charge i ...
22. pyruvate oxidation and citric acid cycle
... been applied because citric acid (Fig. 22–4) is the first intermediate formed in this cycle. The second name has been given in honour of its most illustrious proponent, Sir Hans A. Krebs, who first postulated it in 1937 and the cycle has since then been slightly modified in a form we know today. How ...
... been applied because citric acid (Fig. 22–4) is the first intermediate formed in this cycle. The second name has been given in honour of its most illustrious proponent, Sir Hans A. Krebs, who first postulated it in 1937 and the cycle has since then been slightly modified in a form we know today. How ...
Structure, mechanism and regulation of pyruvate carboxylase
... analysis reveals that the increased metabolic flux through PC is concomitant with stimulation of de novo glutamine synthesis in vivo and ex vivo in the brains of hyperammonaemic animal models [41,42]. A recent report also shows that pyruvate flux through PC varies from 20 % to 50 % of the total pyru ...
... analysis reveals that the increased metabolic flux through PC is concomitant with stimulation of de novo glutamine synthesis in vivo and ex vivo in the brains of hyperammonaemic animal models [41,42]. A recent report also shows that pyruvate flux through PC varies from 20 % to 50 % of the total pyru ...
papain, a plant enzyme of biological importance
... It is often useful to examine the relative hydrophobicity or hydrophilicity values of the amino acids in a protein sequence. Since hydrophobic residues tend to be more buried in the interior of the molecule and hydrophilic residues are more exposed to solvent, a profile of these values can indicate ...
... It is often useful to examine the relative hydrophobicity or hydrophilicity values of the amino acids in a protein sequence. Since hydrophobic residues tend to be more buried in the interior of the molecule and hydrophilic residues are more exposed to solvent, a profile of these values can indicate ...
Enzymes responsible for chlorate reduction by Pseudomonas sp
... consumed for cell respiration and does not accumulate in solution [9]. In perchlorate-respiring bacteria a single enzyme is used for both chlorate and perchlorate reduction, but few enzymes have been isolated. Perchlorate reductases isolated from strains GR-1 [10] and perc1ace [11], and chlorate red ...
... consumed for cell respiration and does not accumulate in solution [9]. In perchlorate-respiring bacteria a single enzyme is used for both chlorate and perchlorate reduction, but few enzymes have been isolated. Perchlorate reductases isolated from strains GR-1 [10] and perc1ace [11], and chlorate red ...
Glycolytic strategy as a tradeoff between energy yield and protein cost
... pathways each contain unique enzymes (marked with *) but also share all of the reactions of lower glycolysis (from G3P through pyruvate). pfk is unique to the glycolytic direction of the EMP pathway, while the edd and eda enzymes are unique to the ED pathway. (C) Ignoring phosphorylation, lower glyc ...
... pathways each contain unique enzymes (marked with *) but also share all of the reactions of lower glycolysis (from G3P through pyruvate). pfk is unique to the glycolytic direction of the EMP pathway, while the edd and eda enzymes are unique to the ED pathway. (C) Ignoring phosphorylation, lower glyc ...
Mechanistic Studies of Two Selected Flavin
... Choline oxidase catalyzes the flavin-dependent, two-step oxidation of choline to glycine betaine via the formation of an aldehyde intermediate. The oxidation of choline includes two reductive half-reactions followed by oxidative half-reactions. In the first oxidation reaction, the alcohol substrate ...
... Choline oxidase catalyzes the flavin-dependent, two-step oxidation of choline to glycine betaine via the formation of an aldehyde intermediate. The oxidation of choline includes two reductive half-reactions followed by oxidative half-reactions. In the first oxidation reaction, the alcohol substrate ...
Nucleotide Metabolism - Oregon State University
... Nucleotide Catabolism Begins with Nucleases to Release Nucleoside Monophosphates Nucleotidases Remove the Phosphate to Make Nucleosides Phosphorylates or Nucleosidases Release Bases and Sugars Adenine-Containing and Guanine Nucleotide Breakdown Processes are Similar, but Deaminases Convert AMP to IM ...
... Nucleotide Catabolism Begins with Nucleases to Release Nucleoside Monophosphates Nucleotidases Remove the Phosphate to Make Nucleosides Phosphorylates or Nucleosidases Release Bases and Sugars Adenine-Containing and Guanine Nucleotide Breakdown Processes are Similar, but Deaminases Convert AMP to IM ...
Enzyme inhibitor
An enzyme inhibitor is a molecule that binds to an enzyme and decreases its activity. Since blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance, many drugs are enzyme inhibitors. They are also used in pesticides. Not all molecules that bind to enzymes are inhibitors; enzyme activators bind to enzymes and increase their enzymatic activity, while enzyme substrates bind and are converted to products in the normal catalytic cycle of the enzyme.The binding of an inhibitor can stop a substrate from entering the enzyme's active site and/or hinder the enzyme from catalyzing its reaction. Inhibitor binding is either reversible or irreversible. Irreversible inhibitors usually react with the enzyme and change it chemically (e.g. via covalent bond formation). These inhibitors modify key amino acid residues needed for enzymatic activity. In contrast, reversible inhibitors bind non-covalently and different types of inhibition are produced depending on whether these inhibitors bind to the enzyme, the enzyme-substrate complex, or both.Many drug molecules are enzyme inhibitors, so their discovery and improvement is an active area of research in biochemistry and pharmacology. A medicinal enzyme inhibitor is often judged by its specificity (its lack of binding to other proteins) and its potency (its dissociation constant, which indicates the concentration needed to inhibit the enzyme). A high specificity and potency ensure that a drug will have few side effects and thus low toxicity.Enzyme inhibitors also occur naturally and are involved in the regulation of metabolism. For example, enzymes in a metabolic pathway can be inhibited by downstream products. This type of negative feedback slows the production line when products begin to build up and is an important way to maintain homeostasis in a cell. Other cellular enzyme inhibitors are proteins that specifically bind to and inhibit an enzyme target. This can help control enzymes that may be damaging to a cell, like proteases or nucleases. A well-characterised example of this is the ribonuclease inhibitor, which binds to ribonucleases in one of the tightest known protein–protein interactions. Natural enzyme inhibitors can also be poisons and are used as defences against predators or as ways of killing prey.