Li_uta_2502D_12817
... coordination typically observed within the non-heme mononuclear iron super family of oxidase/oxygenase enzymes. Furthermore, within 3.3 Å of the CDO active site iron is an unusual covalently crosslinked cysteine-tyrosine pair (C93-Y157). To date, only 3 other enzymes have been identified with a simi ...
... coordination typically observed within the non-heme mononuclear iron super family of oxidase/oxygenase enzymes. Furthermore, within 3.3 Å of the CDO active site iron is an unusual covalently crosslinked cysteine-tyrosine pair (C93-Y157). To date, only 3 other enzymes have been identified with a simi ...
Interactions of TCA cycle enzymes and of the CcpA
... because the association of the complex is faster (ka = 1.7 ± 0.7 x 10 M s ) and the dissociation is slower (kd = ...
... because the association of the complex is faster (ka = 1.7 ± 0.7 x 10 M s ) and the dissociation is slower (kd = ...
REGULATION OF PYRUVATE KINASE AND GLYCEROL
... including large numbers of insects, and many others, rely on the process of diapause to help them survive through regular and predictable environmental barriers to sufficient food and water (Tauber et al., 1986; Collier and Murphy, 1997). Diapause is a physiological process that delays development ...
... including large numbers of insects, and many others, rely on the process of diapause to help them survive through regular and predictable environmental barriers to sufficient food and water (Tauber et al., 1986; Collier and Murphy, 1997). Diapause is a physiological process that delays development ...
13-Alanine as an Ethylene Precursor
... As mentioned, several of the enzymes in this conversion are also part of the proposed scheme for conversion of fl-alanine to ethylene. Thus, the ability of isolated mitochondria to metabolize propionate indicates that at least a portion of the scheme for conversion of /8-alanine to ethylene 'is oper ...
... As mentioned, several of the enzymes in this conversion are also part of the proposed scheme for conversion of fl-alanine to ethylene. Thus, the ability of isolated mitochondria to metabolize propionate indicates that at least a portion of the scheme for conversion of /8-alanine to ethylene 'is oper ...
PATRICK PROBLEMS 2 Key
... Note the presence of the tetrahedral centre bearing the alcohol group - also present in the intermediate. Note also that there is an extra methylene group between this tetrahedral centre and proline. This is necessary if the inhibitor is to be stable to the enzyme. Further details regarding the desi ...
... Note the presence of the tetrahedral centre bearing the alcohol group - also present in the intermediate. Note also that there is an extra methylene group between this tetrahedral centre and proline. This is necessary if the inhibitor is to be stable to the enzyme. Further details regarding the desi ...
Eram_SeyedMohammad - UWSpace
... native molecular weights of 260 kDa. Although the POR of T. maritima was characterized previously, its PDC activity was not reported. Since the T. hypogea genome sequence is not available, the primary structure of the genes encoding each of the POR four subunits were determined using inverse PCR and ...
... native molecular weights of 260 kDa. Although the POR of T. maritima was characterized previously, its PDC activity was not reported. Since the T. hypogea genome sequence is not available, the primary structure of the genes encoding each of the POR four subunits were determined using inverse PCR and ...
- BioMedSearch
... that may have been formed from ADP in the presence of contaminating adenylate kinase (Figure 3). Only about 40% of the PEPS was inactivated which suggested that less than 50% of the PEPS was catalytically phosphorylated during pre-incubation with PEP. This result was investigated further and it was ...
... that may have been formed from ADP in the presence of contaminating adenylate kinase (Figure 3). Only about 40% of the PEPS was inactivated which suggested that less than 50% of the PEPS was catalytically phosphorylated during pre-incubation with PEP. This result was investigated further and it was ...
Purification and Biochemical Characterization of Digestive Lipase in
... of energy. In mammals, lysosomal and digestive lipases have been recognized by several authors (Roussel et al. 1999; Miled et al. 2000). Among digestive lipases, two major groups, gastric and pancreatic lipases, are of fundamental physiological interest because they are responsible for TAG hydrolysi ...
... of energy. In mammals, lysosomal and digestive lipases have been recognized by several authors (Roussel et al. 1999; Miled et al. 2000). Among digestive lipases, two major groups, gastric and pancreatic lipases, are of fundamental physiological interest because they are responsible for TAG hydrolysi ...
Marine Biotecnology
... of energy. In mammals, lysosomal and digestive lipases have been recognized by several authors (Roussel et al. 1999; Miled et al. 2000). Among digestive lipases, two major groups, gastric and pancreatic lipases, are of fundamental physiological interest because they are responsible for TAG hydrolysi ...
... of energy. In mammals, lysosomal and digestive lipases have been recognized by several authors (Roussel et al. 1999; Miled et al. 2000). Among digestive lipases, two major groups, gastric and pancreatic lipases, are of fundamental physiological interest because they are responsible for TAG hydrolysi ...
E. Coli MurG: A Paradigm for a Superfamily of
... present in minute quantities in bacterial cells and thus cannot be isolated readily from natural sources [3,21]. Without suitable substrates to monitor activity, it is not possible to study purified enzymes. Only one structure of an enzyme involved in the late stages of peptidoglycan synthesis was r ...
... present in minute quantities in bacterial cells and thus cannot be isolated readily from natural sources [3,21]. Without suitable substrates to monitor activity, it is not possible to study purified enzymes. Only one structure of an enzyme involved in the late stages of peptidoglycan synthesis was r ...
Serine racemases from barley, Hordeum vulgare L., and other plant
... mammalian serine racemases belong to the fold type II PLP enzymes and that Lys62 which binds to PLP, Phe61 and Gly241, which sandwich the PLP ring, Ser315, the side-chain of which is hydrogen-bonded to the pyridium nitrogen of PLP, and Asn89, which stabilizes the 3’ oxygen of PLP by a hydrogen bond ...
... mammalian serine racemases belong to the fold type II PLP enzymes and that Lys62 which binds to PLP, Phe61 and Gly241, which sandwich the PLP ring, Ser315, the side-chain of which is hydrogen-bonded to the pyridium nitrogen of PLP, and Asn89, which stabilizes the 3’ oxygen of PLP by a hydrogen bond ...
PROTEIN PHOSPHORYLATION AND CELLULAR REGULATION, I by
... enzyme. It was of interest that in the presence of these polyanionic substances, inosinic acid, as well o n 5’-AMP, was very effective as an activator of phosphorylase b. All of these studies on the effects of nucleotides on phosphorylase were carried out before the revelations of Jacob and Monod co ...
... enzyme. It was of interest that in the presence of these polyanionic substances, inosinic acid, as well o n 5’-AMP, was very effective as an activator of phosphorylase b. All of these studies on the effects of nucleotides on phosphorylase were carried out before the revelations of Jacob and Monod co ...
Characterization of the regulatory function of the 46
... reach half of its maximum activity with about 0.2 µM thioredoxin-f (Hutchison et al. 2000) and 4 µM was reported for the plastidic acetyl-CoA carboxylase (Sasaki et al. 1997) under similar experimental conditions. Hence the affinity of the 46-kDa isoform for thioredoxin-f was examined. In contrast t ...
... reach half of its maximum activity with about 0.2 µM thioredoxin-f (Hutchison et al. 2000) and 4 µM was reported for the plastidic acetyl-CoA carboxylase (Sasaki et al. 1997) under similar experimental conditions. Hence the affinity of the 46-kDa isoform for thioredoxin-f was examined. In contrast t ...
The acetyl-CoA pathway of autotrophic growth
... 1945, Barker and Kamen [9], using t4co2, showed that CO 2 was converted to both the methyl and carboxyl positions of acetate. The developments since that time which have led to recognition that ...
... 1945, Barker and Kamen [9], using t4co2, showed that CO 2 was converted to both the methyl and carboxyl positions of acetate. The developments since that time which have led to recognition that ...
Anaerobic respiration with elemental sulfur and with disulfides
... above 10 WM in the growth medium of sulfur-reducing microorganisms growing in the presence of 1 mM HS3 +H2 S at pH s 6. This concentration of polysul¢de sulfur (10 WM) is close to the apparent Km measured with polysul¢de respiration of W. succinogenes [71] (see Table 6). With the assumption that 10 ...
... above 10 WM in the growth medium of sulfur-reducing microorganisms growing in the presence of 1 mM HS3 +H2 S at pH s 6. This concentration of polysul¢de sulfur (10 WM) is close to the apparent Km measured with polysul¢de respiration of W. succinogenes [71] (see Table 6). With the assumption that 10 ...
Peer-reviewed Article PDF
... of 437 amino acid residues are organized into two main subunits, each consisting of 20 alpha-helices. These alpha helices compose approximately 75% of citrate synthase’s tertiary structure. Between these two subunits, a single cleft exists containing the active site. Two binding sites can be found t ...
... of 437 amino acid residues are organized into two main subunits, each consisting of 20 alpha-helices. These alpha helices compose approximately 75% of citrate synthase’s tertiary structure. Between these two subunits, a single cleft exists containing the active site. Two binding sites can be found t ...
The Chemistry and Evolution of Enzyme Function
... subclasses and exhibits great diversity. The current classification of isomerases in six subclasses reduces to two subclasses if the type of isomerism is considered. In addition, the separation of groups of isomerases sharing similar chemistry such as oxidosqualene cyclases and pseudouridine synthas ...
... subclasses and exhibits great diversity. The current classification of isomerases in six subclasses reduces to two subclasses if the type of isomerism is considered. In addition, the separation of groups of isomerases sharing similar chemistry such as oxidosqualene cyclases and pseudouridine synthas ...
Are there errors in glycogen biosynthesis and is laforin a repair
... metabolic function. Since the 1980s, however, it has been recognized that glycogen contains trace amounts of phosphate [16–18], 1 phosphate per 500 to 1500 glucoses in muscle glycogen [2,3]. In mice, this level of phosphorylation is invariant with age [3]. From analyses of rabbit muscle glycogen, th ...
... metabolic function. Since the 1980s, however, it has been recognized that glycogen contains trace amounts of phosphate [16–18], 1 phosphate per 500 to 1500 glucoses in muscle glycogen [2,3]. In mice, this level of phosphorylation is invariant with age [3]. From analyses of rabbit muscle glycogen, th ...
Zymogen Activation Confers Thermodynamic Stability on a Key
... building blocks for protein synthesis are derived from digestion of protein-rich foods, or through the salvage and degradation of cellular and secreted proteins that have passed their useful life span (1). Paradoxically, the proteolytic enzymes evolved to break proteins down into their component ami ...
... building blocks for protein synthesis are derived from digestion of protein-rich foods, or through the salvage and degradation of cellular and secreted proteins that have passed their useful life span (1). Paradoxically, the proteolytic enzymes evolved to break proteins down into their component ami ...
Fatty Acid Biosynthesis
... acetyl ACP is transferred to a sulfhydryl residue of ketoacyl-ACP synthase also known as acyl-malonyl ACP condensing enzyme. The decarboxylation of malonyl ACP generates an enolate anion which is a good nucleophile that attacks the carbonyl of thioester of acetyl-S-KSase to form acetoacetyl ACP. The ...
... acetyl ACP is transferred to a sulfhydryl residue of ketoacyl-ACP synthase also known as acyl-malonyl ACP condensing enzyme. The decarboxylation of malonyl ACP generates an enolate anion which is a good nucleophile that attacks the carbonyl of thioester of acetyl-S-KSase to form acetoacetyl ACP. The ...
THE ATP SYNTHASE—A SPLENDID MOLECULAR MACHINE
... Mg2+ , 5 µM ADP, and 250 µM AMP-PNP. One catalytic site is filled with ADP, another with AMP-PNP, and a third site is empty. All three noncatalytic sites have bound AMP-PNP. Below a central dimple of about 15 Å, the core is filled with helices formed from the C-terminal and N-terminal portions of t ...
... Mg2+ , 5 µM ADP, and 250 µM AMP-PNP. One catalytic site is filled with ADP, another with AMP-PNP, and a third site is empty. All three noncatalytic sites have bound AMP-PNP. Below a central dimple of about 15 Å, the core is filled with helices formed from the C-terminal and N-terminal portions of t ...
Glycogen!Metabolism! ! Glycogen$→!Principal!storage!form!of
... o AMP!(present!significantly!when!ATP!is!depleted)!activates!glycogen! phosphorylase!(R!conformation!enhanced)!and!glycogen!breakdown!is! activated!bc!more!energy!is!needed! o ATP!and!G6P!inhibit!glycogen!phosphorylase!(enhance!the!T!conformation)! ! ∴!glycogen!breakdown!is!inhibited!when!ATP!and!gl ...
... o AMP!(present!significantly!when!ATP!is!depleted)!activates!glycogen! phosphorylase!(R!conformation!enhanced)!and!glycogen!breakdown!is! activated!bc!more!energy!is!needed! o ATP!and!G6P!inhibit!glycogen!phosphorylase!(enhance!the!T!conformation)! ! ∴!glycogen!breakdown!is!inhibited!when!ATP!and!gl ...
Investigating the Role of ADP-forming Acetyl-CoA
... variety of organisms. When the incoming carbon flux surpasses the capacity of central metabolic pathways, excess acetyl-CoA will undergo fermentation and recycle CoA. An additional benefit of acetate fermentation is the generation of energy-containing compounds such as ATP. The production of acetate ...
... variety of organisms. When the incoming carbon flux surpasses the capacity of central metabolic pathways, excess acetyl-CoA will undergo fermentation and recycle CoA. An additional benefit of acetate fermentation is the generation of energy-containing compounds such as ATP. The production of acetate ...
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.