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  • Open Access Icon
  • Research Article
  • Cite Count Icon 3
  • 10.4137/bci.s2676
Synthesis of Capsaicin Glycosides and 8-Nordihydrocapsaicin Glycosides as Potential Weight-Loss Formulations
  • Jan 1, 2010
  • Biochemistry Insights
  • Hisashi Katsuragi + 3 more

The enzymatic synthesis of capsaicin glycosides and 8-nordihydrocapsaicin glycosides was investigated using almond β-glucosidase and cyclodextrin glucanotransferase (CGTase). Capsaicin and 8-nordihydrocapsaicin were converted into their β-glucoside and β-maltooligosaccharide (amylose conjugate), i.e. β-maltoside and β-maltotrioside, by sequencial glycosylation with almond β-glucosidase and CGTase. The β-glucoside and β-maltoside of capsaicin and β-glucoside of 8-nordihydrocapsaicin showed inhibitory effects on high-fat-diet-induced elevations in body weight of mice.

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  • Research Article
  • Cite Count Icon 2
  • 10.4137/bci.s3943
The Use of Soluble Transferrin Receptor in the Detection of rHuEPO abuse in Sports
  • Jan 1, 2010
  • Biochemistry Insights
  • Donovan Mcgrowder + 5 more

Erythropoietin (EPO) increases the number of circulating erythrocytes and muscle oxygenation. The recombinant forms of EPO have indiscriminately been used by athletes, mainly in endurance sports to increase their erythrocytes concentration, thus generating a better delivery of oxygen to the muscle tissue. The administration of recombinant human erythropoietin (rHuEPO) except for therapeutic use was prohibited by the International Olympic Committee (IOC) and its unauthorized use considered as doping. In the last few years, a number of studies using parameters indicative of accelerated erythropoiesis have investigated a number of indirect methods for the detection of rHuEPO abuse. No single indirect marker has been found that can satisfactorily demonstrated rHuEPO misuse. Soluble transferrin receptor (sTfR) is a new marker of iron status and erythropoietic activity. It has been included in multivariable blood testing models for the detection of performance enhancing EPO abuse in sports. Indirect markers of altered erythropoiesis give reliable evidence of current or discontinued rHuEPO usage. This review describes the physical, biological and pharmacokinetic properties of endogenous EPO and its recombinant form. It also discusses the available strategies for the detection of rHuEPO abuse in sports, involving the use of sTfR concentration directly or in mathematical multivariate models.

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  • Research Article
  • Cite Count Icon 4
  • 10.4137/bci.s4231
Preparation of Chiral 2-chloromandelamide: Stereoselective Reduction of an Aromatic α-keto Amide with Actinomycete Strains
  • Jan 1, 2010
  • Biochemistry Insights
  • Kohji Ishihara + 8 more

The stereoselective reduction of an aromatic α-keto amide with actinomycete strains was investigated. It was found that 2-chlorobenzoylformamide was reduced to the corresponding 2-chloromandelamide by mesophilic and thermophilic strains of actinomycetes. Among the strains tested, the reduction of 2-chlorobenzoylformamide by Streptomyces thermocyaneoviolaceus (one of thermophilic strains) in the presence of glycerol as an additive produced only ( S)-2-chloromandelamide in >99% conversion with >99% enantiomeric excess (e.e.). On the other hand, the reduction by Streptomyces thermocarboxydovorans NBRC16324 at 45 °C or Thermoactinomyces vulgaris NBRC15851 cultivated in a soluble starch-based medium gave the corresponding ( R)-hydroxy amide (conversion, 99%; >99% e.e.). Mesophilic and other thermophilic actinomycete strains also catalyzed the reduction to the corresponding (R)-hydroxy amide with 85%–>99% e.e. Thus, the syntheses of both enantiomers of 2-chloromandelamide was achieved though the reduction of 2-chlorobenzoylformamide with different actinomycete strains.

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  • Research Article
  • Cite Count Icon 10
  • 10.4137/bci.s2768
Enzymatic Synthesis and Anti-Allergic Activities of Curcumin Oligosaccharides
  • Jan 1, 2010
  • Biochemistry Insights
  • Kei Shimoda + 1 more

Curcumin 4‘- O-glucooligosaccharides were synthesized by a two step-enzymatic method using almond β-glucosidase and cyclodextrin glucanotransferase (CGTase). Curcumin was glucosylated to curcumin 4‘- O-β-D-glucopyranoside by almond β-glucosidase in 19% yield. Curcumin 4‘- O-β-D-glucopyranoside was converted into curcumin 4‘- O-β-glucooligosaccharides, i.e. 4‘- O-β-maltoside (51%) and 4‘- O-β-maltotrioside (25%), by further CGTase-catalyzed glycosylation. Curcumin 4‘- O-β-glycosides showed suppressive action on IgE antibody formation and inhibitory effects on histamine release from rat peritoneal mast cells.

  • Research Article
  • Cite Count Icon 26
  • 10.4137/bci.s5340
Morphological Changes and Immunohistochemical Expression of RAGE and its Ligands in the Sciatic Nerve of Hyperglycemic Pig (Sus Scrofa)
  • Jan 1, 2010
  • Biochemistry Insights
  • Judyta K Juranek + 11 more

The aim of our project was to study the effect of streptozotocin (STZ)-induced hyperglycemia on sciatic nerve morphology, blood plasma markers and immunohistochemical expression of RAGE (the Receptor for Advanced Glycation End-products), and its ligands-S100B and Carboxymethyl Lysine (CML)-advanced glycation endproduct (AGE) in the laboratory pig. Six months after STZ-injections, blood plasma measurements, morphometric analysis of sciatic nerve fiber density, immunofluorescent distribution of potential molecular neuropathy contributors, ELISA measurement of plasma AGE level and HPLC analysis of sciatic nerve levels of one of the pre-AGE and the glycolysis intermediate products-methyl-glyoxal (MG) were performed. The results of our study revealed that STZ-injected animals displayed elevated levels of plasma glucose, gamma glutamyl transferase (GGT) and triglycerides. The sciatic nerve of STZ-injected pigs revealed significantly lower numbers of small-diameter myelinated fibers, higher immunoreactivity for RAGE and S100B and increased levels of MG as compared to control animals. Our results correspond to clinical findings in human patients with hyperglycemia/diabetes-evoked peripheral neuropathy and suggest that the domestic pig may be a suitable large animal model for the study of mechanisms underlying hyperglycemia-induced neurological complications in the peripheral nerve and may serve as a relevant model for the pre-clinical assessment of candidate drugs in neuropathy.

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  • Research Article
  • Cite Count Icon 2
  • 10.4137/bci.s880
A Novel Mechanism in Regulating the Alpha-Subunit of the Epithelial Sodium Channel (α ENaC) by the Alternatively Spliced Form α ENaC-b
  • Jan 1, 2009
  • Biochemistry Insights
  • Marlene F Shehata

Introduction In Dahl rats’ kidney cortex, the alternatively spliced form of the epithelial sodium channel α subunit (α ENaC-b) is the most abundant mRNA transcript (32+/-3 fold > α ENaC-wt) as was investigated by quantitative RT-PCR analysis. α ENaC-b mRNA levels were significantly higher in Dahl R versus S rats, and were further augmented by high salt diet. Objectives In the present study, we described the molecular cloning and searched for a possible role of α ENaC-b by testing its potential expression in COS7 cells as well as its impact on α ENaC-wt expression levels when co-expressed in COS7 cells in a dose-dependent manner. Methods Using RT-PCR strategy, the full-length wildtype α ENaC transcript and the alternatively spliced form α ENaC-b were amplified, sequenced, cloned, subcloned into PCMV-sport6 expression vector, expressed and co-expressed into COS7 cells in a dose-dependent manner. A combination of denaturing and native western blotting techniques was employed to examine the expression of α ENaC-b in vitro, and to determine if an interaction between α ENaC-b and α ENaC-wt occurs in vitro, and finally to demonstrate if degradation of α ENaC-wt protein does occur. Results α ENaC-b is translated in COS7 cells. Co-expression of α ENaC-b together with α ENaC-wt reduced α ENaC-wt levels in a dose-dependent manner. α ENaC-wt and α ENaC-b appear to form a complex that enhances the degradation of α ENaC-wt. Conclusions Western blots suggest a novel mechanism in α ENaC regulation whereby α ENaC-b exerts a dominant negative effect on α ENaC-wt expression. This is potentially by sequestering α ENaC-wt, enhancing its proteolytic degradation, and possibly explaining the mechanism of salt-resistance in Dahl R rats.

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  • Research Article
  • Cite Count Icon 43
  • 10.4137/bci.s2049
A 20 Residues Motif Delineates the Furin Cleavage Site and its Physical Properties May Influence Viral Fusion
  • Jan 1, 2009
  • Biochemistry Insights
  • Sun Tian

Furin is a proprotein convertase that proteolytically cleaves protein precursors to yield functional proteins. Efficient cleavage depends on the presence of a specific sequence motif on the substrate. Currently, the cleavage site motif is described as a four amino acid pattern: R-X-[K/R]-R⇓. However, not all furin cleavage recognition sites can be described by this pattern and not all R-X-[K/R]-R⇓ sites are cleaved by furin. Since many furin substrates are involved in the pathogenesis of viral infection and human diseases, it is important to accurately characterize the furin cleavage site motif. In this study, the furin cleavage site motif was characterized using statistical analysis. The data were interpreted within the 3D crystal structure of the furin catalytic domain. The results indicate that the furin cleavage site motif is comprised of about 20 residues, P14-P6′. Specific physical properties such as volume, charge, and hydrophilicity are required at specific positions. The furin cleavage site motif is divided into two parts: 1) one core region (8 amino acids, positions P6-P2′) packed inside the furin binding pocket; 2) two polar regions (8 amino acids, positions P7–P14; and 4 amino acids, positions P3′-P6′) located outside the furin binding pocket. The physical properties of the core region contribute to the binding strength of the furin substrate, while the polar regions provide a solvent accessible environment and facilitate the accessibility of the core region to the furin binding pocket. This furin cleavage site motif also revealed a dynamic relationship linking the evolution of physical properties in region P1′-P6′ of viral fusion peptides, furin cleavage efficacy, and viral infectivity.

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  • Research Article
  • Cite Count Icon 7
  • 10.4137/bci.s2257
Fast and Simple microRNA Northern Blots
  • Jan 1, 2009
  • Biochemistry Insights
  • Nham Tran

RNA northern blots provide robust measurements of gene expression. The simple northern blot technique described in this report has been optimised to provide rapid, reproducible detection and analysis of mature and precursor forms of microRNAs. This protocol economises on the use of commercially available components and secondly reduces the hybridisation step to 2 hours.

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  • Research Article
  • Cite Count Icon 2
  • 10.4137/bci.s3745
On Message Ribonucleic Acids Targeting to Mitochondria
  • Jan 1, 2009
  • Biochemistry Insights
  • Di Ding + 2 more

Mitochondria are subcellular organelles that provide energy for a variety of basic cellular processes in eukaryotic cells. Mitochondria maintain their own genomes and many of their endosymbiont genes are encoded by nuclear genomes. The crosstalk between the mitochondrial and nuclear genomes ensures mitochondrial biogenesis, dynamics and maintenance. Mitochondrial proteins are partly encoded by nucleus and synthesized in the cytosol and partly in the mitochondria coded by mitochondrial genome. The efficiency of transport systems that transport nuclear encoded gene products such as proteins and mRNAs to the mitochondrial vicinity to allow for their translation and/or import are recently receiving wide attention. There is currently no concrete evidence that nuclear encoded mRNA is transported into the mitochondria, however, they can be transported onto the mitochondrial surface and translated at the surface of mitochondria utilizing cytosolic machinery. In this review we present an overview of the recent advances in the mRNA transport, with emphasis on the transport of nuclear-encoded mitochondrial protein mRNA into the mitochondria.

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  • Research Article
  • Cite Count Icon 5
  • 10.4137/bci.s2935
Immune- and Pollution-mediated DNA Damage in Two Wild <i>Mya arenaria</i> Clam Populations
  • Jan 1, 2009
  • Biochemistry Insights
  • François Gagné + 2 more

In aquatic environments, genotoxicity results from the effects of pollution combined with the inflammatory response triggered by the immune system. Indeed, the production of nitrosylated DNA and proteins are though to arise from the production of peroxinitrite during phagocytosis and inflammation. The purpose of this study was to examine new DNA biomarkers that differentiate between immune- and pollution-mediated genotoxicity in wild clam populations. Intertidal clam populations were sampled and analyzed for gonadal DNA strand breaks, DNA nitrosylation and xanthine oxidoreductase (XOR) activity (purine salvage pathway). The clam weight-to-shell-length ratio, the gonado-somatic index (GSI), age status, lipid peroxidation, xenobiotic conjugation activity (glutathione S-transferase (GST) and phagocytic activity were examined to shed light on their relationships with the observed genotoxic endpoints. XOR activity and DNA strand breaks were generally elevated at polluted sites and correlated significantly with clam weight-to-shell-length ratios and DNA nitrosylation. DNA nitrosylation was also higher at some sites and correlated significantly with phagocytic activity and with DNA strand breaks. This study showed that DNA strand breaks were associated with both immune-and pollution-mediated effects. This suggests that there is a loss of DNA repair capacity due to the combined effects of aging, pollution and immune response in wild clam populations that are impacted by anthropogenic activity.