Nitrate Reductases: Structure, Functions, and Effect of Stress Factors
... should be noted that the amino acid sequence of Nap from D. desulfuricans is similar to that of assimilatory enzymes. There are a number of serine residues that increase the probability of Mo–O–Ser ligands in Nar compared with formation of Mo–S–Cys ligands found for Nap [7] and predicted for Nas. St ...
... should be noted that the amino acid sequence of Nap from D. desulfuricans is similar to that of assimilatory enzymes. There are a number of serine residues that increase the probability of Mo–O–Ser ligands in Nar compared with formation of Mo–S–Cys ligands found for Nap [7] and predicted for Nas. St ...
Fibroblast Growth Factor Receptor Inhibitors
... active tetrameric form during this process. It forms an inactive dimeric shape while developing new building blocks. Pyruvate kinase type M2 works as a switch between an active tetrameric form and an inactive dimeric form, which is a metabolic sensor as shown in (Fig. 3). Recent studies by Christofk ...
... active tetrameric form during this process. It forms an inactive dimeric shape while developing new building blocks. Pyruvate kinase type M2 works as a switch between an active tetrameric form and an inactive dimeric form, which is a metabolic sensor as shown in (Fig. 3). Recent studies by Christofk ...
A modular approach to sphingolipid analogs mediated by aziridines: Synthesis
... A high variety of complex sphingolipids is known ranking from the simplest sphingosine‐1‐ phosphate to more complex structures such as cerebrosides ‐glucosylceramides and galactosylceramides, or higher glycosilated ceramide species called glycosphingolipids. When galactosylc ...
... A high variety of complex sphingolipids is known ranking from the simplest sphingosine‐1‐ phosphate to more complex structures such as cerebrosides ‐glucosylceramides and galactosylceramides, or higher glycosilated ceramide species called glycosphingolipids. When galactosylc ...
R Is for Arginine Metabolism of Arginine Takes off Again, in New
... concentrations may be limiting for NOS in specific subcellular locales. Moreover, the presence of endogenous competitive inhibitors of NOS (discussed below) may raise the effective intracellular arginine concentration needed for full enzyme activity. In any event, the action of NOS on l-arginine yie ...
... concentrations may be limiting for NOS in specific subcellular locales. Moreover, the presence of endogenous competitive inhibitors of NOS (discussed below) may raise the effective intracellular arginine concentration needed for full enzyme activity. In any event, the action of NOS on l-arginine yie ...
Structure, function and regulation of pyruvate carboxylase
... Glucose is a potent stimulator of insulin secretion from βpancreatic cells when extracellular levels are greater than 3 mM. Secretion of insulin in response to a high concentration of glucose results in the rapid uptake of glucose by pancreatic βcells more than by other cell types [16,17]. This is a ...
... Glucose is a potent stimulator of insulin secretion from βpancreatic cells when extracellular levels are greater than 3 mM. Secretion of insulin in response to a high concentration of glucose results in the rapid uptake of glucose by pancreatic βcells more than by other cell types [16,17]. This is a ...
R Is for Arginine
... concentrations may be limiting for NOS in specific subcellular locales. Moreover, the presence of endogenous competitive inhibitors of NOS (discussed below) may raise the effective intracellular arginine concentration needed for full enzyme activity. In any event, the action of NOS on l-arginine yie ...
... concentrations may be limiting for NOS in specific subcellular locales. Moreover, the presence of endogenous competitive inhibitors of NOS (discussed below) may raise the effective intracellular arginine concentration needed for full enzyme activity. In any event, the action of NOS on l-arginine yie ...
pH-induced conformational changes in human ABO(H) blood group
... upon substrate binding at near-neutral pH. GTA more readily assumes the closed state, whereas GTB tends to remain in the open state, with the chimeric enzymes showing intermediate behavior correlated to their relative homology to GTA or GTB (Letts et al. 2006; Alfaro et al. 2008). The same trend is ...
... upon substrate binding at near-neutral pH. GTA more readily assumes the closed state, whereas GTB tends to remain in the open state, with the chimeric enzymes showing intermediate behavior correlated to their relative homology to GTA or GTB (Letts et al. 2006; Alfaro et al. 2008). The same trend is ...
A number of antibiotics produced by different - J
... which has been shown to be an inhibitor of yeast RNA polymerases in vitro6,7) and it has been suggested that prokaryotic RNA synthesis is also sensitive to this antibiotic8,9). However, we found that the RNA polymerases of the five organisms used in this study were unaffected by thiolutin in vitro ( ...
... which has been shown to be an inhibitor of yeast RNA polymerases in vitro6,7) and it has been suggested that prokaryotic RNA synthesis is also sensitive to this antibiotic8,9). However, we found that the RNA polymerases of the five organisms used in this study were unaffected by thiolutin in vitro ( ...
Pyruvate Dehydrogenase
... • There is a net gain of 2 ATP per glucose molecule • As glucose is oxidized, two NAD+ are reduced to 2 NADH ...
... • There is a net gain of 2 ATP per glucose molecule • As glucose is oxidized, two NAD+ are reduced to 2 NADH ...
Document
... Fifteen possible isomers of protoporphyrinogen can form Normal mitochondrial physiology leads to the formation of only one of these isomers (protoporphyrinogen IX) Protoporphyrinogen oxidase is involved in this reaction and oxygen as a hydrogen acceptor ...
... Fifteen possible isomers of protoporphyrinogen can form Normal mitochondrial physiology leads to the formation of only one of these isomers (protoporphyrinogen IX) Protoporphyrinogen oxidase is involved in this reaction and oxygen as a hydrogen acceptor ...
Nomenclature of Nucleotides and Nucleosides
... Lesch-Nyhan syndrome Cause. Lesch-Nyhan syndrome is a hereditary X-linked recessive condition that is due to a severe or complete deficiency of HGPRT activity. c. Increased synthesis of purines. Because there is little or no HGPRT activity in people affected with Lesch-Nyhan syndrome, hypoxanthine a ...
... Lesch-Nyhan syndrome Cause. Lesch-Nyhan syndrome is a hereditary X-linked recessive condition that is due to a severe or complete deficiency of HGPRT activity. c. Increased synthesis of purines. Because there is little or no HGPRT activity in people affected with Lesch-Nyhan syndrome, hypoxanthine a ...
Chapter 2: Biochemistry Problems
... In these problems, you will be given the covalent bonds (these are shown as solid lines) and must infer their noncovalent bonding properties. Noncovalent bonds/interactions are shown by dotted lines (etc.). These two types of “bonds” are entirely separate; for example, an oxygen (which can make only ...
... In these problems, you will be given the covalent bonds (these are shown as solid lines) and must infer their noncovalent bonding properties. Noncovalent bonds/interactions are shown by dotted lines (etc.). These two types of “bonds” are entirely separate; for example, an oxygen (which can make only ...
PLP-dependent Enzymes: a Powerful Tool for - Beilstein
... Enzymes are generally believed to be very specific in their action, i. e. to be endowed with a strict reaction and substrate specificity. However, as a matter of fact, many enzymes are able to catalyze more than one reaction, often using different substrates. These enzymes are called generalist in o ...
... Enzymes are generally believed to be very specific in their action, i. e. to be endowed with a strict reaction and substrate specificity. However, as a matter of fact, many enzymes are able to catalyze more than one reaction, often using different substrates. These enzymes are called generalist in o ...
Purification and Characterization of
... centrifugation at 1,110g for 10 min. The cells were resuspended to a final concentration of 5 3 107 cells mL21 in 50 mm Hepes buffer (pH 7.8) that contained 10 mm MgCl2, 0.1% b-mercaptoethanol, and 1 mm PMSF as a protease inhibitor. This mixture was stored at 270°C for later use. An atmosphere of N2 ...
... centrifugation at 1,110g for 10 min. The cells were resuspended to a final concentration of 5 3 107 cells mL21 in 50 mm Hepes buffer (pH 7.8) that contained 10 mm MgCl2, 0.1% b-mercaptoethanol, and 1 mm PMSF as a protease inhibitor. This mixture was stored at 270°C for later use. An atmosphere of N2 ...
acetyl CoA carboxylase
... 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 ...
Plant Physiology 66:
... (18). A clear distinction may be drawn between this liquid, originating from the integuments, and the endosperm, which is transient and never becomes fully cellular (17, 18). This fluid diminishes in volume as the embryo expands but persists as a sticky coating around the embryo throughout seed deve ...
... (18). A clear distinction may be drawn between this liquid, originating from the integuments, and the endosperm, which is transient and never becomes fully cellular (17, 18). This fluid diminishes in volume as the embryo expands but persists as a sticky coating around the embryo throughout seed deve ...
biochemistry - Textbooks Online
... 2. They speed up the process of attaining equilibrium 3. They do not need energy for their transport. 4. They are highly specific in nature. ...
... 2. They speed up the process of attaining equilibrium 3. They do not need energy for their transport. 4. They are highly specific in nature. ...
Small-molecule metabolism: an enzyme mosaic
... were used in the present study. The results of the domain assignment procedure (shown in Box 1 and described in detail in Ref. 2) gave a total of 722 domains in 213 families in 510 (88%) of the E. coli small-molecule metabolism (SMM) enzymes (summarized in Box 2 and Table 1). There are, on average, ...
... were used in the present study. The results of the domain assignment procedure (shown in Box 1 and described in detail in Ref. 2) gave a total of 722 domains in 213 families in 510 (88%) of the E. coli small-molecule metabolism (SMM) enzymes (summarized in Box 2 and Table 1). There are, on average, ...
Influence of Metal Ions on Ruminal Enzyme Activities Nutritional
... incubated for 30 min at 37 °C prior to enzyme activity assay in the rumen fluid with or without metal ions using spectrophotometric methods. Cadmium was found to inhibit urease, GDH, and GGT activity but on the other hand, it stimulated ALT and AST activity. Copper inhibited both GDH and urease acti ...
... incubated for 30 min at 37 °C prior to enzyme activity assay in the rumen fluid with or without metal ions using spectrophotometric methods. Cadmium was found to inhibit urease, GDH, and GGT activity but on the other hand, it stimulated ALT and AST activity. Copper inhibited both GDH and urease acti ...
02 Cholesterol Metabolism2012-03-18 01:50617 KB
... • Phosphorylated form of enzyme is inactive • Dephosphorylated form is active • High ATP cholesterol synthesis stops • Low ATP cholesterol synthesis starts ...
... • Phosphorylated form of enzyme is inactive • Dephosphorylated form is active • High ATP cholesterol synthesis stops • Low ATP cholesterol synthesis starts ...
Facultative Anaerobiosis in the Invertebrates: Pathways and Control
... or pyruvate is decarboxylated to PEP which can then serve as a precursor of glycogen, the overall process being referred to as glyconeogenesis. Most significant is the fact that mammalian tissues utilize PEP rapidly in the presence of ADP to form pyruvate and ATP (reaction 1). This reaction is catal ...
... or pyruvate is decarboxylated to PEP which can then serve as a precursor of glycogen, the overall process being referred to as glyconeogenesis. Most significant is the fact that mammalian tissues utilize PEP rapidly in the presence of ADP to form pyruvate and ATP (reaction 1). This reaction is catal ...
... • Direct coupling uses the energy released when ATP is converted to ADP + Pi to drive the reaction. The transfer of energy occurs within the active site of the enzyme, i.e. both ATP and the substrate are bound on the same enzyme (3 pts) Examples (+1 pt): Any kinase: hexose kinase, PFK-1, PFK-2. • In ...
The shikimate pathway in apicomplexan parasites: Implications for
... DHQase) catalyzes the third step in the shikimate pathway, which is the dehydration of 3-dehydroquinate to 3dehydroshikimate. Dehydroquinases are classified into two distinct types (I and II), which are structurally and mechanistically different (see Table 1) (26, 27). Type I DHQases catalyze the sy ...
... DHQase) catalyzes the third step in the shikimate pathway, which is the dehydration of 3-dehydroquinate to 3dehydroshikimate. Dehydroquinases are classified into two distinct types (I and II), which are structurally and mechanistically different (see Table 1) (26, 27). Type I DHQases catalyze the sy ...
How does it vary with the charge and distance of the ions?
... 2. a) Write down the Lewis structure for CNO and OCN ions and comment on each. b) The C-Cl distance in CH3Cl and CF3Cl are 1.78A0 and 1.75A0 respectively. Explain. c) Predict the shapes of the following with the VSEPR theory – i) XeF4 ii) CIF3 iii) SF4 iv) PCl4. d) Show with the help of molecular or ...
... 2. a) Write down the Lewis structure for CNO and OCN ions and comment on each. b) The C-Cl distance in CH3Cl and CF3Cl are 1.78A0 and 1.75A0 respectively. Explain. c) Predict the shapes of the following with the VSEPR theory – i) XeF4 ii) CIF3 iii) SF4 iv) PCl4. d) Show with the help of molecular or ...
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.