cyclo-(tryptophanyl-prolyl)

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Isolation and characterization of cyclo-(tryptophanyl-prolyl) and chloramphenicol from Streptomyces sp. SUK 25 with antimethicillin-resistant Staphylococcus aureus activity

Isolation and characterization of cyclo-(tryptophanyl-prolyl) and chloramphenicol from Streptomyces sp. SUK 25 with antimethicillin-resistant Staphylococcus aureus activity

bacteria resistance against antibiotic has become a serious problem worldwide. From this view, attempts have been made to extract, identify, and evaluate the active metabolites from SUK 25 against MRSA, and two compounds, namely, cyclo-(tryptophanyl-prolyl), which is a type of cyclic dipep- tides diketopiperazines (DKPs), and chloramphenicol (CAP) have been isolated from this strain. Cyclic dipeptides DKPs or 2,5-DKPs, also known as dipeptide anhydrides (DPKs), are relatively simple compounds. Therefore, they are among the most common peptide derivatives found in nature. 20 DPKs

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Isolation and characterization of <em>cyclo</em>-(tryptophanyl-prolyl) and chloramphenicol from <em>Streptomyces sp</em>. SUK 25 with antimethicillin-resistant <em>Staphylococcus aureus</em> activity

Isolation and characterization of <em>cyclo</em>-(tryptophanyl-prolyl) and chloramphenicol from <em>Streptomyces sp</em>. SUK 25 with antimethicillin-resistant <em>Staphylococcus aureus</em> activity

bacteria resistance against antibiotic has become a serious problem worldwide. From this view, attempts have been made to extract, identify, and evaluate the active metabolites from SUK 25 against MRSA, and two compounds, namely, cyclo-(tryptophanyl-prolyl), which is a type of cyclic dipep- tides diketopiperazines (DKPs), and chloramphenicol (CAP) have been isolated from this strain. Cyclic dipeptides DKPs or 2,5-DKPs, also known as dipeptide anhydrides (DPKs), are relatively simple compounds. Therefore, they are among the most common peptide derivatives found in nature. 20 DPKs

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Effects of selected cyclo-oxygenase inhibitors on cardiovascular preparations in rabbits

Effects of selected cyclo-oxygenase inhibitors on cardiovascular preparations in rabbits

Cyclo-oxygenase- (COX-) inhibitors are those drugs which have the ability to inhibit the activity of COX enzymes (types 1 and 2) resulting in inhibition of prostaglandin synthesis [1]. Two types of COX- inhibitors are established, the traditional non-selective non-steroidal anti-inflammatory drugs (NSAIDs) which block both types of COX. The second type is the selective COX-2 inhibitors which have no or minimal affinity, and thus, no effect on COX-1. The development of the COX-2 selective inhibitors was intended to provide drugs that would offer the same pain-relieving and anti-inflammatory effects as the traditional NSAIDs without causing the gastric ulcers and nephrotic effects that have been associated with the pioneer drugs [2].

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A Novel Dihydropyridines C Glycosylated Compound by Hantzsch Cyclo Condensation

A Novel Dihydropyridines C Glycosylated Compound by Hantzsch Cyclo Condensation

DOI: 10.4236/ojsta.2018.72002 18 Open Journal of Synthesis Theory and Applications 1,4-DHPs are synthesized by Hantzsch method which involves cyclo conden- sation of an aldehyde, β -diketone and ammonia in acetic acid which leads to de- rivatives of dihydropyridines. The synthesis of Dihydropyridines C-Glycosylated has importance because of their good pharmacokinetic and the role of com- pound in molecular recognition [6]. Dondoni has reported the synthesis and use of a designed glycosylated compound in some of the possible combinations in Hantzsch synthesis. He prepared them as a collection of C-nucleosides dihydro- pyridines compounds and some exhibiting significant biological activities have been reported [7] [8] [9] [10].

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cyclo Bis­(par­aquat m ter­phenyl­ene) tetra­kis­­(hexa­fluoro­phosphate) tetrahydrate

cyclo Bis­(par­aquat m ter­phenyl­ene) tetra­kis­­(hexa­fluoro­phosphate) tetrahydrate

(Scheytza et al., 1999), but these values are larger than those reported for cyclo-bis(paraquat-p-phenylene) tetrakis(hexa- ¯uorophosphate) (Odell et al., 1988). The overall dimensions of the macrocyclic tetracation are 13.23 AÊ between the centroids of the bonds connecting pyridinium rings and 12.86 AÊ between C12 and C12 i [symmetry code: (i) ÿx, 1 ÿ y,

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Chicken Cyclo-oxygenases Response in a Pulmonary Infection Disease

Chicken Cyclo-oxygenases Response in a Pulmonary Infection Disease

Quantitative real-time PCR analysis indicates that COX-1 mRNA is expressed in lungs, heart, pancreas and colon, with relatively different level. Whereas, it was not detected in the small intestine and liver. We noted also a wide distribution of COX-2 in tissues from normal hens, including lung, small intestine, liver, spleen and heart with relative expression level of 7.13, 3.54, 2.81, 1.83 and 1.17, respectively. These results, confirms that Cyclo-oxygenase enzymes with distinct cell- specific expression and regulation are essential for normal physiological processes yet their aberrant expression is a critical factor in a host of pathologies. In mammals, COX-2 is present in various neoplasms, such as colorectal, lung, stomach, pancreas, breast, urinary, bladder and esophageal neoplasms [16]. Whereas, COX-1 is constitutively expressed and related to physiological functions [17].

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Exploiting the Expressiveness of Cyclo-Static Dataflow to Model Multimedia Implementations

Exploiting the Expressiveness of Cyclo-Static Dataflow to Model Multimedia Implementations

The design of increasingly complex and concurrent multimedia systems requires a description at a higher abstraction level. Using an appropriate model of computation helps to reason about the system and enables design time analysis methods. The nature of multimedia processing matches in many cases well with cyclo-static dataflow (CSDF), making it a suitable model. However, channels in an implementation often use for cost reasons a kind of shared buffer that cannot be directly described in CSDF. This paper shows how such implementation specific aspects can be expressed in CSDF without the need for extensions. Consequently, the CSDF graph remains completely analyzable and allows reasoning about its temporal behavior. The obtained relation between model and implementation enables a buffer capacity analysis on the model while assuring the throughput of the final implemen- tation. The capabilities of the approach are demonstrated by analyzing the temporal behavior of an MPEG-4 video encoder with a CSDF graph.

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Cyclomatrix polyphosphazenes frameworks (Cyclo POPs) and the related nanomaterials : synthesis, assembly and functionalisation

Cyclomatrix polyphosphazenes frameworks (Cyclo POPs) and the related nanomaterials : synthesis, assembly and functionalisation

Phosphorous-containing covalent organic frameworks (cyclo-POP) represent a novel type of porous functional hybrids along with covalent organic frameworks (COFs) and metal organic frameworks (MOFs). The cyclo-POP materials have distinguished themselves in the world of porous molecular composites in the follow aspects: (1) a library of compounds with dual- or tri-functional groups are applicable as co-monomers to react with HCCP. The morphology of cyclo-POPs are tuneable by varying the types of monomer and solvent as well as the reaction conditions; (2) cyclo-POPs are formed via a one-step polycondensation reaction at ambient conditions which is obviously advantageous over those synthesis protocols for COFs and MOFs; (3) The functionalities of the cyclo-POPs can be designed by molecular structuring by introducing functional co-monomers (such as fluorescein, fluorine, radical-containing moieties); post-functionalisation of the assembled cyclo-POP nanoparticles by polymer grafting, doping with metal/metal salts nanoparticles, or encapsulating nanoparticles; (4) the highly crosslinked cyclo-POP derived carbon nanoparticles are desirable for energy storage, due to their hierarchical porous structure, intrinsically doped heteroatoms, mechanical robustness and electro- chemical activity.

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Calcium potassium cyclo triphosphate

Calcium potassium cyclo triphosphate

al., 2003), we report here the crystal structure of a hexagonal high-temperature modi®cation of calcium potassium cyclo- triphosphate. A rhombohedral modi®cation (Andrieu et al., 1966) and an orthorhombic modi®cation (Masse et al., 1975) have also been found for CaKP 3 O 9 . The present structure is

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Cyclo(L tyrosyl L tryptophanyl) di­methylformamide solvate

Cyclo(L tyrosyl L tryptophanyl) di­methylformamide solvate

From the 20 naturally occurring amino acids one can construct 210 different cyclic dipeptides (as opposed to 400 linear dipeptides). Single crystal structural studies have been presented for 20 of them, including four structures with Tyr or Trp residues: cyclo(Gly-Trp) (Morris et al., 1974), cyclo(Trp-Trp) DMSO solvate (Grant et al., 1999), cyclo(Leu-Tyr) hydrate (Suguna et al., 1984), and cyclo(Ser-Tyr) hydrate (Lin & Webb, 1973). From a conformational point of view these four peptides resemble (I) as well as each other, and all except cyclo(Trp-Trp) crystallize in the P2 1 space group. Nevertheless,

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Genetic Validation of Aminoacyl-tRNA Synthetases as Drug Targets in Trypanosoma brucei

Genetic Validation of Aminoacyl-tRNA Synthetases as Drug Targets in Trypanosoma brucei

Human African trypanosomiasis (HAT) is an important public health threat in sub-Saharan Africa. Current drugs are unsatis- factory, and new drugs are being sought. Few validated enzyme targets are available to support drug discovery efforts, so our goal was to obtain essentiality data on genes with proven utility as drug targets. Aminoacyl-tRNA synthetases (aaRSs) are known drug targets for bacterial and fungal pathogens and are required for protein synthesis. Here we survey the essentiality of eight Trypanosoma brucei aaRSs by RNA interference (RNAi) gene expression knockdown, covering an enzyme from each major aaRS class: valyl-tRNA synthetase (ValRS) (class Ia), tryptophanyl-tRNA synthetase (TrpRS-1) (class Ib), arginyl-tRNA synthetase (ArgRS) (class Ic), glutamyl-tRNA synthetase (GluRS) (class 1c), threonyl-tRNA synthetase (ThrRS) (class IIa), asparaginyl- tRNA synthetase (AsnRS) (class IIb), and phenylalanyl-tRNA synthetase ( ␣ and ␤ ) (PheRS) (class IIc). Knockdown of mRNA encoding these enzymes in T. brucei mammalian stage parasites showed that all were essential for parasite growth and survival in vitro. The reduced expression resulted in growth, morphological, cell cycle, and DNA content abnormalities. ThrRS was char- acterized in greater detail, showing that the purified recombinant enzyme displayed ThrRS activity and that the protein localized to both the cytosol and mitochondrion. Borrelidin, a known inhibitor of ThrRS, was an inhibitor of T. brucei ThrRS and showed antitrypanosomal activity. The data show that aaRSs are essential for T. brucei survival and are likely to be excellent targets for drug discovery efforts.

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Digestion and assimilation of proline containing peptides by rat intestinal brush border membrane carboxypeptidases  Role of the combined action of angiotensin converting enzyme and carboxypeptidase P

Digestion and assimilation of proline containing peptides by rat intestinal brush border membrane carboxypeptidases Role of the combined action of angiotensin converting enzyme and carboxypeptidase P

Two intestinal brush border membrane carboxypeptidases were found to participate in the sequential digestion of proline-containing peptides representing a novel mechanism of hydrolysis from the COOH terminus. NH2-blocked prolyl tripeptides were rapidly hydrolyzed by either brush border membrane angiotensin converting enzyme (ACE, dipeptidyl

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Sandwich ELISA for quantitative detection of human collagen prolyl 4-hydroxylase

Sandwich ELISA for quantitative detection of human collagen prolyl 4-hydroxylase

The method developed in this study is relevant to quanti- tative collagen prolyl-4-hydroxylase detection for moni- toring the recombinant C-P4H production and C-P4H coexpression during recombinant collagens production. The specificity of the antibodies used in the assay against the different collagen prolyl-4-hydroxylase subunits ensures detection of the holoenzyme only, but not its sep- arate subunits. Using an experimental design approach the antibody concentrations in the ELISA were opti- mized. The method was successfully applied for monitor- ing the recombinant C-P4H amount in crude cell extracts of E. coli during the optimization of C-P4H production. This study demonstrates the sandwich ELISA applicabil- ity for quantifying of proteins consisting of different sub- units in crude samples. The method is potential for recombinant multimeric proteins production monitor- ing as well as complex proteins detection in clinical and food diagnostics.

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Overexpressed tryptophanyl-tRNA synthetase, an angiostatic protein, enhances oral cancer cell invasiveness

Overexpressed tryptophanyl-tRNA synthetase, an angiostatic protein, enhances oral cancer cell invasiveness

Oral squamous cell carcinoma (OSCC) is one of the most common neoplasms worldwide. Previously, we identified the angiostatic agent tryptophanyl-tRNA synthetase (TrpRS) as a dysregulated protein in OSCC based on a proteomics approach. Herein, we show that TrpRS is overexpressed in OSCC tissues (139/146, 95.2%) compared with adjacent normal tissues and that TrpRS expression positively correlates with tumor stage, overall TNM stage, perineural invasion and tumor depth. Importantly, the TrpRS levels were significantly higher in tumor cells from metastatic lymph nodes than in corresponding primary tumor cells. TrpRS knockdown or treatment with conditioned media obtained from TrpRS-knockdown cells significantly reduced oral cancer cell viability and invasiveness. TrpRS overexpression promoted cell migration and invasion. In addition, the extracellular addition of TrpRS rescued the invasion ability of TrpRS-knockdown cells. Subcellular fractionation and immunofluorescence staining further revealed that TrpRS was distributed on the cell surface, suggesting that secreted TrpRS promotes OSCC progression via an extrinsic pathway. Collectively, our results demonstrated the clinical significance and a novel role of TrpRS in OSCC.

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Prolyl hydroxylase domain enzymes: important regulators of cancer metabolism

Prolyl hydroxylase domain enzymes: important regulators of cancer metabolism

Abstract: The hypoxia-inducible factor (HIF) prolyl hydroxylase domain enzymes (PHDs) regulate the stability of HIF protein by post-translational hydroxylation of two conserved prolyl residues in its α subunit in an oxygen-dependent manner. Trans-4-prolyl hydroxylation of HIFα under normal oxygen (O 2 ) availability enables its association with the von Hippel-Lindau (VHL) tumor suppressor pVHL E3 ligase complex, leading to the degradation of HIFα via the ubiquitin- proteasome pathway. Due to the obligatory requirement of molecular O 2 as a co-substrate, the activity of PHDs is inhibited under hypoxic conditions, resulting in stabilized HIFα, which dimerizes with HIFβ and, together with transcriptional co-activators CBP/p300, activates the transcription of its target genes. As a key molecular regulator of adaptive response to hypoxia, HIF plays important roles in multiple cellular processes and its overexpression has been detected in various cancers. The HIF1α isoform in particular has a strong impact on cellular metabolism, most notably by promoting anaerobic, whilst inhibiting O 2 -dependent, metabolism of glucose. The PHD enzymes also seem to have HIF-independent functions and are subject to regulation by factors other than O 2 , such as by metabolic status, oxidative stress, and abnormal levels of endogenous metabolites (oncometabolites) that have been observed in some types of cancers. In this review, we aim to summarize current understandings of the function and regulation of PHDs in cancer with an emphasis on their roles in metabolism.

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Prolyl-hydroxylase 3: evolving roles for an ancient signaling protein

Prolyl-hydroxylase 3: evolving roles for an ancient signaling protein

Abstract: The ability of cells to sense oxygen is a highly evolved process that facilitates adap- tations to the local oxygen environment and is critical to energy homeostasis. In vertebrates, this process is largely controlled by three intracellular prolyl-4-hydroxylases (PHD) 1–3. These related enzymes share the ability to hydroxylate the hypoxia-inducible transcription factor (HIF), and therefore control the transcription of genes involved in metabolism and vascular recruitment. However, it is becoming increasingly apparent that PHD controls much more than HIF signaling, with PHD3 emerging as an exceptionally unique and functionally diverse PHD isoform. In fact, PHD3-mediated hydroxylation has recently been purported to function in such diverse roles as sympathetic neuronal and muscle development, sepsis, glycolytic metabolism, and cell fate. PHD3 expression is also highly distinct from that of the other PHD enzymes, and varies considerably between different cell types and oxygen concentrations. This review will examine the evolution of oxygen sensing by the HIF family of PHD enzymes, with a specific focus on the complex nature of PHD3 expression and function in mammalian cells.

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Prolyl oligopeptidase is inhibited in relapsing-remitting multiple sclerosis

Prolyl oligopeptidase is inhibited in relapsing-remitting multiple sclerosis

Important variations in activity and stability of POP due to preparation and assay conditions have been noticed before [30]. On the other hand, two different enzymes in plasma, with prolyl endopeptidase activity, have been described [31]. Apart from classical POP, the alternative activity is insensitive to POP-specific inhibitors, and is called Z-Pro-Prolinal insensitive peptidase or ZIP. This activity has been attributed to the action of fibrinogen activated protein α (FAPα) or seprase [32]. On the other hand, Breen and collaborators [31] have reported that cation chelators, which are currently used during plasma preparation, affect POP activity. Our experiments indi- cate that while neither citrate nor EDTA in the plasma affected the levels of ZIP activity (Fig. 1A), activity of POP, or the Z-pro-prolinal sensitive activity level, was found to be substantially lower in the presence of citrate (p < 0.05). EDTA-containing plasma seems to have higher levels of POP (Fig. 1B). To verify the sensitivity to these

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Released Tryptophanyl-tRNA Synthetase Stimulates Innate Immune Responses against Viral Infection

Released Tryptophanyl-tRNA Synthetase Stimulates Innate Immune Responses against Viral Infection

Aminoacyl-tRNA synthetases (ARSs) are essential enzymes that catalyze the ligation of specific amino acids to their cognate tRNAs (34). In addition to their canonical role in translation, ARSs in higher organisms possess additional domains or novel motifs that mediate diverse noncanonical functions in processes such as cell metabolism, tumorigenesis, angiogenesis, and innate immunity (35–38). These noncanonical func- tions of ARSs are not confined to the cytosol, where their role in linking amino acids to tRNAs is carried out, but occur in the nucleus or in the extracellular space after secretion. Human tryptophanyl-tRNA synthetase (WRS) also carries out additional func- tions. Inside the nucleus, WRS stimulates DNA-dependent protein kinase, catalytic subunit (DNA-PKcs), activity via its WHEP domain, leading to the phosphorylation and activation of p53 (39). In addition, the miniature form of WRS, which lacks the 47 N- terminal amino acids, is secreted into the extracellular space and inhibits angiogenesis by interacting with VE-cadherin (40). Recently, a role for WRS in innate immunity against bacterial infection was reported. However, its specific role in the response to viral infection has not been clarified in detail (41).

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Characterizing the domain- and phosphorylation-requirements of the interaction between peptidyl prolyl isomerase Pin1 and mitotic phosphatase CDC25C

Characterizing the domain- and phosphorylation-requirements of the interaction between peptidyl prolyl isomerase Pin1 and mitotic phosphatase CDC25C

In spite of the evidence confirming the ability of Pin1 to catalyze cis-trans isomerisation, there are still questions concerning its precise catalytic mechanism. On the basis of a crystal structure of Pin1, Ranganathan et al. (9), initially proposed a mechanism that involved the formation of a covalent enzyme-substrate intermediate with Cys113, His59, and His157 being key residues involved in catalysis. Since then, however, additional evidence has argued instead for a non-covalent mechanism. In this respect, Lippens et al. (14) proposed that the role of Cys113 is to destabilize the peptide prolyl bond to allow for its rotation. This hypothesis is supported by data from Behrsin et al. (15) showing that a Cys113/Asp substitution did not abolish Pin1 function. Additionally, with regards to the histidine residues, it has been shown that they do not directly participate in catalysis, suggesting they instead act structurally to support the integrity of the active site (16).

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The prolyl isomerase Pin1 in breast development and cancer

The prolyl isomerase Pin1 in breast development and cancer

Recent studies indicate that phosphorylation-dependent prolyl isomerization is a new post-phosphorylation signal- ing mechanism that plays an important role in diverse cel- lular processes. Importantly, this mechanism has provided new insights into breast development and cancer. Pin1 is overexpressed in breast cancer and may function to trans- late or amplify multiple oncogenic signaling mechanisms during oncogenesis. In contrast, inhibition of Pin1 could provide a unique way of disrupting oncogenic pathways and therefore represent an appealing target for anticancer therapies. A major challenge for the future will be to develop various animal models to further elucidate the molecular mechanisms by which Pin1 regulates breast development and cancer and to define the interactions between Pin1 and other oncogenes or tumor suppressors involved in breast cancer. Another major challenge will be to develop Pin1-specific inhibitors and to evaluate their potential for treating breast cancer.

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