BMC BIOCHEMISTRY

Application of WST-8 based colorimetric NAD(P)H detection for quantitative dehydrogenase assays
Chamchoy K, Pakotiprapha D, Pumirat P, Leartsakulpanich U and Boonyuen U
The reduction of tetrazolium salts by NAD(P)H to formazan product has been widely used to determine the metabolic activity of cells, and as an indicator of cell viability. However, the application of a WST-8 based assay for the quantitative measurement of dehydrogenase enzyme activity has not been described before. In this study, we reported the application of an assay based on the tetrazolium salt WST-8 for the quantitative measurement of dehydrogenase activity. The assay is performed in a microplate format, where a single endpoint is measured at 450 nm.
Association of TM6SF2 rs58542926 gene polymorphism with the risk of non-alcoholic fatty liver disease and colorectal adenoma in Chinese Han population
Li Y, Liu S, Gao Y, Ma H, Zhan S, Yang Y, Xin Y and Xuan S
Genetic factors affect the risk of non-alcoholic fatty liver disease (NAFLD) and colorectal adenoma (CRA) importantly. Transmembrane protein 6 superfamily member 2 (TM6SF2) rs58542926 is a significant genetic susceptibility site for NAFLD. The relationships of TM6SF2 rs58542926 with the risk of NAFLD and CRA in Chinese Han population were unclear. The aim of this study was to investigate the association of TM6SF2 rs58542926 with the risk of NAFLD and CRA, and the effect of CRA on TM6SF2 rs58542926 carried NAFLD patients.
Role of the highly conserved G68 residue in the yeast phosphorelay protein Ypd1: implications for interactions between histidine phosphotransfer (HPt) and response regulator proteins
Kennedy EN, Hebdon SD, Menon SK, Foster CA, Copeland DM, Xu Q, Janiak-Spens F and West AH
Many bacteria and certain eukaryotes utilize multi-step His-to-Asp phosphorelays for adaptive responses to their extracellular environments. Histidine phosphotransfer (HPt) proteins function as key components of these pathways. HPt proteins are genetically diverse, but share a common tertiary fold with conserved residues near the active site. A surface-exposed glycine at the H + 4 position relative to the phosphorylatable histidine is found in a significant number of annotated HPt protein sequences. Previous reports demonstrated that substitutions at this position result in diminished phosphotransfer activity between HPt proteins and their cognate signaling partners.
The active role of the transcription factor Sp1 in NFATc2-mediated gene regulation in pancreatic cancer
Malsy M, Graf B and Almstedt K
Adenocarcinoma of the pancreas is one of the most aggressive tumor diseases affecting the human body. The oncogenic potential of pancreatic cancer is mainly characterized by extremely rapid growth triggered by the activation of oncogenic signaling cascades, which suggests a change in the regulation of important transcription factors. Amongst others, NFAT transcription factors are assumed to play a central role in the carcinogenesis of pancreatic cancer. Recent research has shown the importance of the transcription factor Sp1 in the transcriptional activity of NFATc2 in pancreatic cancer. However, the role of the interaction between these two binding partners remains unclear. The current study investigated the role of Sp1 proteins in the expression of NFATc2 target genes and identified new target genes and their function in cells. A further objective was the domain of the Sp1 protein that mediates interaction with NFATc2. The involvement of Sp1 proteins in NFATc2 target genes was shown by means of a gene expression profile analysis, and the results were confirmed by quantitative RT-PCR. The functional impact of this interaction was shown in a thymidine incorporation assay. A second objective was the physical interaction between NFATc2 and different Sp1 deletion mutants that was investigated by means of immunoprecipitation.
Purification and characterization of cysteine protease from miswak Salvadora persica
Abdulaal WH
Generally, proteases in medicinal plants had different therapeutic effects such as anti-inflammatory effect; modulate the immune response and inhibitory effect toward tumor growth. In this study, protease was purified and characterized from miswak roots, as medicinal plant and natural toothbrush.
Identification of the major diacylglycerol acyltransferase mRNA in mouse adipocytes and macrophages
Cao H
Triacylglycerols (TAGs) are the major form of energy storage in eukaryotes. Diacylglycerol acyltransferases (DGATs) catalyze the final and rate-limiting step of TAG biosynthesis. Mammalian DGATs are classified into DGAT1 and DGAT2 subfamilies. It was unclear which DGAT was the major isoform expressed in animal cells. The objective was to identify the major DGAT mRNA expressed in cultured mouse adipocytes and macrophages and compared it to that expressed in tung tree seeds.
Soluble expression of recombinant midgut zymogen (native propeptide) proteases from the Aedes aegypti Mosquito Utilizing E. coli as a host
Nguyen JT, Fong J, Fong D, Fong T, Lucero RM, Gallimore JM, Burata OE, Parungao K and Rascón AA
Studying proteins and enzymes involved in important biological processes in the Aedes aegypti mosquito is limited by the quantity that can be directly isolated from the mosquito. Adding to this difficulty, digestive enzymes (midgut proteases) involved in metabolizing blood meal proteins require a more oxidizing environment to allow proper folding of disulfide bonds. Therefore, recombinant techniques to express foreign proteins in Escherichia coli prove to be effective in producing milligram quantities of the expressed product. However, with the most commonly used strains having a reducing cytoplasm, soluble expression of recombinant proteases is hampered. Fortunately, new E. coli strains with a more oxidizing cytoplasm are now available to ensure proper folding of disulfide bonds.
Up-regulation of DcR3 in microbial toxins-stimulated HUVECs involves NF-κB signalling
Hou Y, Liang D, Liu Y, Chen H and Lou X
Sepsis is a severe condition characterised by the body's systemic inflammatory response to infection. The specific sepsis-related biomarkers should be used in clinical diagnosis, therapeutic response monitoring, rational use of antibiotics, and prognosis (risk stratification), etc. RESULTS: In this study, we investigated the expression level of Decoy Receptor 3 (DcR3) and the mechanism of high expression in sepsis patients. Septic cell model experiments were performed by treating human umbilical vein endothelial cells (HUVECs) and Jurkat cells with lipopolysaccharide (LPS), lipoteichoic acid (LTA) and zymosan, respectively. SP600125, SB203580 and ammonium pyrrolidinedithiocarbamate (PDTC) were used to inhibit JNK1/2, p38MAPK and NF-κB signalling pathways in septic cell model, respectively. These results showed that DcR3 levels were higher in sepsis group than control. DcR3 mRNA and protein levels in HUVECs were increased following treatment with LPS, LTA and zymosan, and also increased in Jurkat cells treated by LPS, but not by LTA or zymosan. When HUVECs were treated with the NF-κB inhibitor PDTC, DcR3 expression was decreased compared with controls. However, SP600125 and SB203580 had no effect on DcR3 mRNA or protein levels.
Effect of IAPP on the proteome of cultured Rin-5F cells
Miraee-Nedjad S, Sims PFG, Schwartz JM and Doig AJ
Islet amyloid polypeptide (IAPP) or amylin deposits can be found in the islets of type 2 diabetes patients. The peptide is suggested to be involved in the etiology of the disease through formation of amyloid deposits and destruction of β islet cells, though the underlying molecular events leading from IAPP deposition to β cell death are still largely unknown.
Structure and function of a lignostilbene-α,β-dioxygenase orthologue from Pseudomonas brassicacearum
Loewen PC, Switala J, Wells JP, Huang F, Zara AT, Allingham JS and Loewen MC
Stilbene cleaving oxygenases (SCOs), also known as lignostilbene-α,β-dioxygenases (LSDs) mediate the oxidative cleavage of the olefinic double bonds of lignin-derived intermediate phenolic stilbenes, yielding small modified benzaldehyde compounds. SCOs represent one branch of the larger carotenoid cleavage oxygenases family. Here, we describe the structural and functional characterization of an SCO-like enzyme from the soil-born, bio-control agent Pseudomonas brassicacearum.
Simple spectrophotometric assay for measuring catalase activity in biological tissues
Hadwan MH
The details of a precise, accurate, and sensitive spectrophotometric method for measuring catalase activity are presented here. The assay was established for biological samples and depends on the rapid formation of a stable and colored carbonato-cobaltate (III) complex. Samples exhibiting catalase activity are incubated with hydrogen peroxide solution for 2 min prior to rapid mixing of the incubation enzymatic reaction mixture with cobalt-bicarbonate reagent, which assesses non-reacting hydrogen peroxide. Catalase activity is always directly proportional to the rate of dissociation of hydrogen peroxide. Hydrogen peroxide acts to oxidize cobalt (II) to cobalt (III) in the presence of bicarbonate ions; this process ends with the production of a carbonato-cobaltate (III) complex ([Co (CO)]Co). The formed end product has two maximum absorbance peaks: 440 nm and 640 nm. The 440-nm peak has been utilized for assessing catalase activity.
Establishment of a detection assay for DNA endonuclease activity and its application in the screening and prognosis of malignant lymphoma
Lu R, Wang Y, Xu X, Xie S, Wang Y, Zhong A, Zheng H, Yu Y, Gao X and Guo L
Endonucleases play critical roles in maintaining genomic stability and regulating cell growth. The purpose of this study was to evaluate detection of endonuclease activity as an indicator in the early diagnosis and prognosis of lymphoma.
Purification and characterization of α-amylase from Trichoderma pseudokoningii
Abdulaal WH
Previous studies have demonstrated that members of Trichoderma are able to generate appreciable amount of extracellular amylase and glucoamylase on soluble potato starch. In this study the α-amylase was purified and characterized from Trichoderma pseudokoningii grown on orange peel under solid state fermentation (SSF).
Isolation of quercetin and mandelic acid from Aesculus indica fruit and their biological activities
Zahoor M, Shafiq S, Ullah H, Sadiq A and Ullah F
In this study Aesculus indica fruit was subjected to isolation of phytochemicals. Two antioxidants quercetin and Mandelic acid were isolated in pure state. The free radical scavenging and acetyl choline esterase inhibitory potential of the crude extract and sub fractions were also determined.
Identification and characterization of smallest pore-forming protein in the cell wall of pathogenic Corynebacterium urealyticum DSM 7109
Abdali N, Younas F, Mafakheri S, Pothula KR, Kleinekathöfer U, Tauch A and Benz R
Corynebacterium urealyticum, a pathogenic, multidrug resistant member of the mycolata, is known as causative agent of urinary tract infections although it is a bacterium of the skin flora. This pathogenic bacterium shares with the mycolata the property of having an unusual cell envelope composition and architecture, typical for the genus Corynebacterium. The cell wall of members of the mycolata contains channel-forming proteins for the uptake of solutes.
Characterization of association of human mitochondrial lysyl-tRNA synthetase with HIV-1 Pol and tRNA
Khoder-Agha F, Dias JM, Comisso M and Mirande M
An important step in human immunodeficiency virus type 1 (HIV-1) replication is the packaging of tRNA from the host cell, which plays the role of primer RNA in the process of initiation of reverse transcription. The viral GagPol polyprotein precursor, and the human mitochondrial lysyl-tRNA synthetase (mLysRS) from the host cell, have been proposed to be involved in the packaging process. More specifically, the catalytic domain of mLysRS is supposed to interact with the transframe (TF or p6*) and integrase (IN) domains of the Pol region of the GagPol polyprotein.
Feruloyl esterase immobilization in mesoporous silica particles and characterization in hydrolysis and transesterification
Bonzom C, Schild L, Gustafsson H and Olsson L
Enzymes display high reactivity and selectivity under natural conditions, but may suffer from decreased efficiency in industrial applications. A strategy to address this limitation is to immobilize the enzyme. Mesoporous silica materials offer unique properties as an immobilization support, such as high surface area and tunable pore size.
Characterization of sulfhydryl oxidase from Aspergillus tubingensis
Nivala O, Faccio G, Arvas M, Permi P, Buchert J, Kruus K and Mattinen ML
Despite of the presence of sulfhydryl oxidases (SOXs) in the secretomes of industrially relevant organisms and their many potential applications, only few of these enzymes have been biochemically characterized. In addition, basic functions of most of the SOX enzymes reported so far are not fully understood. In particular, the physiological role of secreted fungal SOXs is unclear.
Glycyl-alanyl-histidine protects PC12 cells against hydrogen peroxide toxicity
Shimura H, Tanaka R, Shimada Y, Yamashiro K, Hattori N and Urabe T
Peptides with cytoprotective functions, including antioxidants and anti-infectives, could be useful therapeutics. Carnosine, β-alanine-histidine, is a dipeptide with anti-oxidant properties. Tripeptides of Ala-His-Lys, Pro-His-His, or Tyr-His-Tyr are also of interest in this respect.
Antiproliferative factor (APF) binds specifically to sites within the cytoskeleton-associated protein 4 (CKAP4) extracellular domain
Chavda B, Ling J, Majernick T and Planey SL
Antiproliferative factor (APF) is a sialoglycopeptide elevated in the urine of patients with interstitial cystitis-a chronic, painful bladder disease. APF inhibits the proliferation of normal bladder epithelial cells and cancer cells in vitro, presumably by binding to its cellular receptor, cytoskeleton associated-protein 4 (CKAP4); however, the biophysical interaction of APF with CKAP4 has not been characterized previously. In this study, we used surface plasmon resonance (SPR) to explore the binding kinetics of the interaction of APF and as-APF (a desialylated APF analogue with full activity) to CKAP4.
Use of a special Brazilian red-light emitting railroad worm Luciferase in bioassays of NEK7 protein Kinase and Creatine Kinase
Marina Perez A, Aquino B, Viviani V and Kobarg J
Luciferases, enzymes that catalyze bioluminescent reactions in different organisms, have been extensively used for bioanalytical purposes. The most well studied bioluminescent system is that of firefly and other beetles, which depends on a luciferase, a benzothiazolic luciferin and ATP, and it is being widely used as a bioanalytical reagent to quantify ATP. Protein kinases are proteins that modify other proteins by transferring phosphate groups from a nucleoside triphosphate, usually ATP.