Displaying publications 41 - 60 of 92 in total

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  1. Fulltext IgG4 detection of Echinococcus granulosus paramyosin is a useful diagnostic test for human hydatidosis
    Moghadam ZK, Ghaffarifar F, Khalilpour A, Abdul Aziz F, Saadatnia G, Noordin R
    Clin Vaccine Immunol, 2013 Apr;20(4):501-5.
    PMID: 23365208 DOI: 10.1128/CVI.00019-13
    Hydatidosis is a public health problem in many parts of the world, and improvement in diagnosis of the disease is still being pursued. Protoscoleces of Echinococcus granulosus were isolated from hydatid cysts collected from naturally infected sheep slaughtered in abattoirs in Iran. Sonicated extract of protoscolex was subjected to two-dimensional gel electrophoresis and Western blot analysis. Primary antibodies were from serum samples from 130 hydatidosis patients, 38 individuals infected with other parasitic infections, and 30 healthy people, whereas peroxidase (HRP)-conjugated anti-human IgG and IgG4 were used as secondary antibodies. The recombinant form of the identified protein was produced and tested for its sensitivity and specificity for the detection of human hydatidosis. An antigenic band of ∼60 kDa was found to be sensitive (82%) and specific (100%) for the detection of hydatidosis when probed with anti-human IgG4-HRP, while the sensitivity and specificity were 33 and 100%, respectively, with anti-human IgG-HRP. By mass spectrometry, the band was identified as protoscolex tegument paramyosin. The sensitivity and specificity of full-length paramyosin-recombinant protein in IgG4 blots were found to be 86 and 98%, respectively. In conclusion, IgG4 detection of Echinococcus granulosus paramyosin was found to be useful for the diagnosis of human hydatidosis.
    Matched MeSH terms: Recombinant Proteins/chemistry
  2. Fulltext Crystallization and preliminary X-ray analysis of recombinant Glomerella cingulata cutinase
    Nyon MP, Rice DW, Berrisford JM, Huang H, Moir AJ, Craven CJ, et al.
    Acta Crystallogr Sect F Struct Biol Cryst Commun, 2008 Jun 01;64(Pt 6):504-8.
    PMID: 18540061 DOI: 10.1107/S1744309108012086
    Cutinase catalyzes the hydrolysis of water-soluble esters and long-chain triglycerides and belongs to the family of serine hydrolases. The enzyme is thought to represent an evolutionary link between the esterase and lipase families and has potential applications in a wide range of industrial hydrolytic processes, for which an understanding of the molecular basis of its substrate specificity is critical. Glomerella cingulata cutinase has been cloned and the protein has been overexpressed in Escherichia coli, purified and subsequently crystallized in a wide range of different crystal forms in the presence and absence of inhibitors. The best crystals are those of the apo cutinase, which diffract to beyond 1.6 A resolution and belong to space group P4(1)2(1)2 or P4(3)2(1)2. Crystals of cutinase with the inhibitors PETFP or E600 belong to space groups P2(1)2(1)2(1) and P2(1), respectively, and diffract to approximately 2.5 A resolution. All of the crystals are suitable for structural studies, which are currently ongoing.
    Matched MeSH terms: Recombinant Proteins/chemistry
  3. A novel organic solvent tolerant lipase from Bacillus sphaericus 205y: extracellular expression of a novel OST-lipase gene
    Sulong MR, Abdul Rahman RN, Salleh AB, Basri M
    Protein Expr Purif, 2006 Oct;49(2):190-5.
    PMID: 16769222
    An organic solvent tolerant (OST) lipase gene from Bacillus sphaericus 205y was successfully expressed extracellularly. The expressed lipase was purified using two steps purification; ultrafiltration and hydrophobic interaction chromatography (HIC) to 8-fold purity and 32% recovery. The purified 205y lipase revealed homogeneity on denaturing gel electrophoresis and the molecular mass was at approximately 30 kDa. The optimum pH for the purified 205y lipase was 7.0-8.0 and its stability showed a broad range of pH value between pH 5.0 to 13.0 at 37 degrees C. The purified 205y lipase exhibited an optimum temperature of 55 degrees C. The activity of the purified lipase was stimulated in the presence of Ca2+ and Mg2+. Ethylenediaminetetraacetic acid (EDTA) has no effect on its activity; however inhibition was observed with phenylmethane sulfonoyl fluoride (PMSF) a serine hydrolase inhibitor. Organic solvents such as dimethylsulfoxide (DMSO), methanol, p-xylene and n-decane enhanced the activity. Studies on the effect of oil showed that the lipase was most active in the presence of tricaprin (C10). The lipase exhibited 1,3 positional specificity.
    Matched MeSH terms: Recombinant Proteins/chemistry
  4. Unscrambling the effect of C-terminal tail deletion on the stability of a cold-adapted, organic solvent stable lipase from Staphylococcus epidermidis AT2
    Kamarudin NH, Rahman RN, Ali MS, Leow TC, Basri M, Salleh AB
    Mol Biotechnol, 2014 Aug;56(8):747-57.
    PMID: 24771007 DOI: 10.1007/s12033-014-9753-1
    Terminal moieties of most proteins are long known to be disordered and flexible. To unravel the functional role of these regions on the structural stability and biochemical properties of AT2 lipase, four C-terminal end residues, (Ile-Thr-Arg-Lys) which formed a flexible, short tail-like random-coil segment were targeted for mutation. Swapping of the tail-like region had resulted in an improved crystallizability and anti-aggregation property along with a slight shift of the thermostability profile. The lipolytic activity of mutant (M386) retained by 43 % compared to its wild-type with 18 % of the remaining activity at 45 °C. In silico analysis conducted at 25 and 45 °C was found to be in accordance to the experimental findings in which the RMSD values of M386 were more stable throughout the total trajectory in comparison to its wild-type. Terminal moieties were also observed to exhibit large movement and flexibility as denoted by high RMSF values at both dynamics. Variation in organic solvent stability property was detected in M386 where the lipolytic activity was stimulated in the presence of 25 % (v/v) of DMSO, isopropanol, and diethyl ether. This may be worth due to changes in the surface charge residues at the mutation point which probably involve in protein-solvent interaction.
    Matched MeSH terms: Recombinant Proteins/chemistry
  5. Fulltext Production of recombinant Entamoeba histolytica pyruvate phosphate dikinase and its application in a lateral flow dipstick test for amoebic liver abscess
    Saidin S, Yunus MH, Zakaria ND, Razak KA, Huat LB, Othman N, et al.
    BMC Infect Dis, 2014 Apr 04;14:182.
    PMID: 24708664 DOI: 10.1186/1471-2334-14-182
    BACKGROUND: Amoebic liver abscess (ALA) is the most common clinical manifestation of extraintestinal amoebiasis especially in developing countries, causing up to 100 000 fatal cases annually. Accurate and early diagnosis is important to prevent the disease complications, however its diagnosis still poses many challenges due to the limitations of the available detection tools. Pyruvate phosphate dikinase (PPDK), an excretory-secretory protein of E. histolytica, has been reported as a potential diagnostic marker for ALA, hence it may be exploited in the development of a new test for ALA.

    METHODS: Recombinant PPDK (rPPDK) was expressed, purified and evaluated by Western blot. In parallel, recombinant galactose-and-N-acetyl-D-galactosamine inhibitable lectin (Gal/GalNAc lectin) was produced and tested similarly. The protein identity was confirmed by analysis using MALDI-TOF/TOF. A lateral flow dipstick (LFD) test using rPPDK was subsequently developed (rPPDK-LFD) and evaluated for serodiagnosis of ALA.

    RESULTS: rPPDK was expressed as soluble protein after 4 hours of induction with 1 mM isopropyl β-D-1-thiogalactopyranoside (IPTG) at 30°C. Purification using nickel-nitrilotriacetic acid (Ni-NTA) resin yielded 1.5 mg of rPPDK from 1 L of culture with estimated molecular mass of 98 kDa on SDS-PAGE. Western blots using sera from patients with ALA, healthy individuals and other diseases probed with anti-human IgG4-HRP showed the highest sensitivity (93.3%) and specificity (100%); as compared to blots using IgG and IgG1 as secondary antibodies. Moreover, rPPDK showed better specificity when compared to rGal/GalNAc lectin. In the development of the LFD test, the optimum amount of rPPDK was 0.625 μg per dipstick and the optimum working concentration of colloidal gold conjugated anti-human IgG4 was optical density (OD) 5 (1.7 μg of anti-human IgG4). Evaluation of rPPDK-LFD using ALA patients and controls serum samples showed 87% diagnostic sensitivity and 100% specificity.

    CONCLUSION: The developed rPPDK-LFD showed good potential for rapid diagnosis of ALA, and merit further multicentre validation using larger number of serum samples.

    Matched MeSH terms: Recombinant Proteins/chemistry
  6. Statistical optimization of green fluorescent protein production from Escherichia coli BL21(DE3)
    Chew FN, Tan WS, Boo HC, Tey BT
    Prep Biochem Biotechnol, 2012;42(6):535-50.
    PMID: 23030465 DOI: 10.1080/10826068.2012.660903
    An optimized cultivation condition is needed to maximize the functional green fluorescent protein (GFP) production. Six process variables (agitation rate, temperature, initial medium pH, concentration of inducer, time of induction, and inoculum density) were screened using the fractional factorial design. Three variables (agitation rate, temperature, and time of induction) exerted significant effects on functional GFP production in E. coli shake flask cultivation and were optimized subsequently using the Box-Behnken design. An agitation rate of 206 rpm at 31°C and induction of the protein expression when the cell density (OD(600nm)) reaches 1.04 could enhance the yield of functional GFP production from 0.025 g/L to 0.241 g/L, which is about ninefold higher than the unoptimized conditions. Unoptimized cultivation conditions resulted in protein aggregation and hence reduced the quantity of functional GFP. The model and regression equation based on the shake flask cultivation could be applied to a 2-L bioreactor for maximum functional GFP production.
    Matched MeSH terms: Recombinant Proteins/chemistry
  7. Fulltext Engineering the production of major catechins by Escherichia coli carrying metabolite genes of Camellia sinensis
    Umar KM, Abdulkarim SM, Radu S, Abdul Hamid A, Saari N
    ScientificWorldJournal, 2012;2012:529031.
    PMID: 22645428 DOI: 10.1100/2012/529031
    A mimicked biosynthetic pathway of catechin metabolite genes from C. sinensis, consisting of flavanone 3 hydroxylase (F3H), dihydroflavonol reductase (DFR), and leucoanthocyanidin reductase (LCR), was designed and arranged in two sets of constructs: (a) single promoter in front of F3H and ribosome-binding sequences both in front of DFR and LCR; (b) three different promoters with each in the front of the three genes and ribosome-binding sequences at appropriate positions. Recombinant E. coli BL (DE3) harbouring the constructs were cultivated for 65 h at 26 °C in M9 medium consisting of 40 g/L glucose, 1 mM IPTG, and 3 mM eriodictyol. Compounds produced were extracted in ethyl acetate in alkaline conditions after 1 h at room temperature and identified by HPLC. Two of the four major catechins, namely, (-)-epicatechin (0.01) and (-)-epicatechin gallate (0.36 mg/L), and two other types ((+)-catechin hydrate (0.13 mg/L) and (-)-catechin gallate (0.04 mg/L)) were successfully produced.
    Matched MeSH terms: Recombinant Proteins/chemistry
  8. Bacteriocin release protein-mediated secretory expression of recombinant chalcone synthase in Escherichia coli
    Zakaria II, Rahman RN, Salleh AB, Basri M
    Appl Biochem Biotechnol, 2011 Sep;165(2):737-47.
    PMID: 21633820 DOI: 10.1007/s12010-011-9292-1
    Flavonoids are secondary metabolites synthesized by plants shown to exhibit health benefits such as anti-inflammatory, antioxidant, and anti-tumor effects. Thus, due to the importance of this compound, several enzymes involved in the flavonoid pathway have been cloned and characterized in Escherichia coli. However, the formation of inclusion bodies has become a major disadvantage of this approach. As an alternative, chalcone synthase from Physcomitrella patens was secreted into the medium using a bacteriocin release protein expression vector. Secretion of P. patens chalcone synthase into the culture media was achieved by co-expression with a psW1 plasmid encoding bacteriocin release protein in E. coli Tuner (DE3) plysS. The optimized conditions, which include the incubation of cells for 20 h with 40 ng/ml mitomycin C at OD(600) induction time of 0.5 was found to be the best condition for chalcone synthase secretion.
    Matched MeSH terms: Recombinant Proteins/chemistry
  9. Gene expression and functional studies of small heat shock protein 37 (MrHSP37) from Macrobrachium rosenbergii challenged with infectious hypodermal and hematopoietic necrosis virus (IHHNV)
    Arockiaraj J, Vanaraja P, Easwvaran S, Singh A, Othman RY, Bhassu S
    Mol Biol Rep, 2012 Jun;39(6):6671-82.
    PMID: 22290288 DOI: 10.1007/s11033-012-1473-7
    In this study, we have reported a full length of small heat shock protein 37 (designated MrHSP37) gene, identified from the transcriptome database of freshwater prawn Macrobrachium rosenbergii. The complete gene sequence of the MrHSP37 is 2,425 base pairs in length, and encodes 338 amino acids. MrHSP37 contains a long heat shock protein family profile in the amino acid sequence between 205 and 288. The mRNA expressions of MrHSP37 in healthy and the infectious hypodermal and hematopoietic necrosis virus (IHHNV) challenged M. rosenbergii were examined using quantitative real time polymerase chain reaction (qRT-PCR). MrHSP37 is highly expressed in hepatopancreas and all the other tissues (walking leg, gills, muscle, stomach, haemocyte, intestine, pleopods, brain and eye stalk) of M. rosenbergii taken for analysis. The expression is strongly up-regulated after IHHNV challenge. To understand its biological activity, the recombinant MrHSP37 gene was constructed and expressed in Escherichia coli BL21 (DE3). The results of ATPase assay showed that the recombinant MrHSP37 protein exhibited apparent ATPase activity which increased with the concentration of the protein. And also the purified recombinant MrHSP37 protein was used for thermal aggregation assay (chaperone activity). It showed that the recombinant MrHSP37 protein is an active chaperone in this assay. Taken together, these results suggest that MrHSP37 is potentially involved in the immune responses against IHHNV challenge in M. rosenbergii.
    Matched MeSH terms: Recombinant Proteins/chemistry
  10. Fulltext Molecular cloning, expression and biochemical characterisation of a cold-adapted novel recombinant chitinase from Glaciozyma antarctica PI12
    Ramli AN, Mahadi NM, Rabu A, Murad AM, Bakar FD, Illias RM
    Microb Cell Fact, 2011;10:94.
    PMID: 22050784 DOI: 10.1186/1475-2859-10-94
    Cold-adapted enzymes are proteins produced by psychrophilic organisms that display a high catalytic efficiency at extremely low temperatures. Chitin consists of the insoluble homopolysaccharide β-(1, 4)-linked N-acetylglucosamine, which is the second most abundant biopolymer found in nature. Chitinases (EC 3.2.1.14) play an important role in chitin recycling in nature. Biodegradation of chitin by the action of cold-adapted chitinases offers significant advantages in industrial applications such as the treatment of chitin-rich waste at low temperatures, the biocontrol of phytopathogens in cold environments and the biocontrol of microbial spoilage of refrigerated food.
    Matched MeSH terms: Recombinant Proteins/chemistry
  11. Fulltext Klebsiella pneumoniae yggG gene product: a zinc-dependent metalloprotease
    Kuan CS, Wong MT, Choi SB, Chang CC, Yee YH, Wahab HA, et al.
    Int J Mol Sci, 2011;12(7):4441-55.
    PMID: 21845088 DOI: 10.3390/ijms12074441
    Klebsiella pneumoniae causes neonatal sepsis and nosocomial infections. One of the strains, K. pneumoniae MGH 78578, shows high level of resistance to multiple microbial agents. In this study, domain family, amino acid sequence and topology analyses were performed on one of its hypothetical protein, YggG (KPN_03358). Structural bioinformatics approaches were used to predict the structure and functionality of YggG protein. The open reading frame (ORF) of yggG, which was a putative metalloprotease gene, was also cloned, expressed and characterized. The ORF was PCR amplified from K. pneumoniae MGH 78578 genomic DNA and cloned into a pET14-b vector for heterologous expression in Escherichia coli. The purified YggG protein was subsequently assayed for casein hydrolysis under different conditions. This protein was classified as peptidase M48 family and subclan gluzincin. It was predicted to contain one transmembrane domain by TMpred. Optimal protein expression was achieved by induction with 0.6 mM isopropyl thiogalactoside (IPTG) at 25 °C for six hours. YggG was purified as soluble protein and confirmed to be proteolytically active under the presence of 1.25 mM zinc acetate and showed optimum activity at 37 °C and pH 7.4. We confirmed for the first time that the yggG gene product is a zinc-dependent metalloprotease.
    Matched MeSH terms: Recombinant Proteins/chemistry
  12. Organic-solvent stability of elastase strain K overexpressed in an Escherichia-Pseudomonas expression system
    Wong CF, Salleh AB, Basri M, Abd Rahman RN
    Biotechnol Appl Biochem, 2010 Sep;57(1):1-7.
    PMID: 20726840 DOI: 10.1042/BA20100224
    The structural gene of elastase strain K (elastase from Pseudomonas aeruginosa strain K), namely HindIII1500PstI, was successfully sequenced to contain 1497 bp. The amino acid sequence, deduced from the nucleotide sequence, revealed that the mature elastase consists of 301 amino acids, with a molecular mass of 33.1 kDa, and contains a conserved motif HEXXH, zinc ligands and residues involved in the catalysis of elastase strain K. The structural gene was successfully cloned to a shuttle vector, pUCP19, and transformed into Escherichia coli strains TOP10, KRX, JM109 and Tuner™ pLacI as well as P. aeruginosa strains PA01 (A.T.C.C. 47085) and S5, with detection of significant protein expression. Overexpression was detected from transformants KRX/pUCP19/HindIII1500PstI of E. coli and PA01/pUCP19/HindIII1500PstI of P. aeruginosa, with increases in elastolytic activity to 13.83- and 5.04-fold respectively relative to their controls. In addition, recombinant elastase strain K showed considerable stability towards numerous organic solvents such as methanol, ethanol, acetone, toluene, undecan-1-ol and n-dodecane, which typically pose a detrimental effect on enzymes; our finding provides further information to support the potential application of the enzyme in synthetic industries, particularly peptide synthesis.
    Matched MeSH terms: Recombinant Proteins/chemistry*
  13. Characterization of hbzE-encoded gentisate 1,2-dioxygenase from Pseudomonas alcaligenes NCIMB 9867
    Yeo CC, Tan CL, Gao X, Zhao B, Poh CL
    Res. Microbiol., 2007 Sep;158(7):608-16.
    PMID: 17720458
    Pseudomonas alcaligenes NCIMB 9867 (strain P25X) is known to synthesize two isofunctional gentisate 1,2-dioxygenases (GDO; EC 1.13.11.4) as well as other enzymes involved in the degradation of xylenols and cresols via the gentisate pathway. The hbzE gene encoding what is possibly the strictly inducible gentisate 1,2-dioxygenase II (GDO-II) was cloned, overexpressed and purified as a hexahistidine fusion protein from Escherichia coli. Active recombinant GDO-II had an estimated molecular mass of 150kDa and is likely a tetrameric protein with a subunit mass of approximately 40kDa, similar to the previously characterized gentisate 1,2-dioxygenase I (GDO-I) encoded by xlnE. However, GDO-II was unable to utilize gentisate that is substituted at the carbon-4 position, unlike GDO-I which had broader substrate specificity. GDO-II also possessed different kinetic characteristics when compared to GDO-I. The hbzE-encoded GDO-II shared higher sequence identities (53%) with GDOs from Ralstonia sp. U2 and Polaromonas naphthalenivorans CJ2, compared with only 35% identity with the xlnE-encoded GDO-I. The hbzE gene was found to be part of a cluster of nine genes including the putative regulatory gene designated hbzR, which encodes an LysR-type regulator and is divergently transcribed from the other genes of the hbzHIJKLFED cluster.
    Matched MeSH terms: Recombinant Proteins/chemistry
  14. Native agarose gel electrophoresis and electroelution: A fast and cost-effective method to separate the small and large hepatitis B capsids
    Yoon KY, Tan WS, Tey BT, Lee KW, Ho KL
    Electrophoresis, 2013 Jan;34(2):244-53.
    PMID: 23161478 DOI: 10.1002/elps.201200257
    Hepatitis B core antigen (HBcAg) expressed in Escherichia coli is able to self-assemble into large and small capsids comprising 240 (triangulation number T = 4) and 180 (triangulation number T = 3) subunits, respectively. Conventionally, sucrose density gradient ultracentrifugation and SEC have been used to separate these capsids. However, good separation of the large and small particles with these methods is never achieved. In the present study, we employed a simple, fast, and cost-effective method to separate the T = 3 and T = 4 HBcAg capsids by using native agarose gel electrophoresis followed by an electroelution method (NAGE-EE). This is a direct, fast, and economic method for isolating the large and small HBcAg particles homogenously based on the hydrodynamic radius of the spherical particles. Dynamic light scattering analysis demonstrated that the T = 3 and T = 4 HBcAg capsids prepared using the NAGE-EE method are monodisperse with polydispersity values of ∼15% and ∼13%, respectively. ELISA proved that the antigenicity of the capsids was not affected in the purification process. Overall, NAGE-EE produced T = 3 and T = 4 capsids with a purity above 90%, and the recovery was 34% and 50%, respectively (total recovery of HBcAg is ∼84%), and the operation time is 15 and 4 times lesser than that of the sucrose density gradient ultracentrifugation and SEC, respectively.
    Matched MeSH terms: Recombinant Proteins/chemistry
  15. Purification of long helical capsid of newcastle disease virus from Escherichia coli using anion exchange chromatography
    Yap CF, Tan WS, Sieo CC, Tey BT
    Biotechnol Prog, 2013 Mar-Apr;29(2):564-7.
    PMID: 23364925 DOI: 10.1002/btpr.1697
    NP(Δc375) is a truncated version of the nucleocapsid protein of Newcastle disease virus (NDV) which self-assembles into a long helical structure. A packed bed anion exchange chromatography (PB-AEC), SepFastTM Supor Q pre-packed column, was used to purify NP(Δc375) from clarified feedstock. This PB-AEC column adsorbed 76.2% of NP(Δc375) from the clarified feedstock. About 67.5% of the adsorbed NP(Δc375) was successfully eluted from the column by applying 50 mM Tris-HCl elution buffer supplemented with 0.5 M NaCl at pH 7. Thus, a recovery yield of 51.4% with a purity of 76.7% which corresponds to a purification factor of 6.5 was achieved in this PB-AEC operation. Electron microscopic analysis revealed that the helical structure of the NP(Δc375) purified by SepFast(TM) Supor Q pre-packed column was as long as 490 nm and 22-24 nm in diameter. The antigenicity of the purified NP(Δc375) was confirmed by enzyme-linked immunosorbent assay.
    Matched MeSH terms: Recombinant Proteins/chemistry
  16. Heterologous expression of human cytochrome P450 (CYP) 2C19 in Escherichia coli and establishment of RP-HPLC method to serve as activity marker
    Pan Y, Mak JW, Ong CE
    Biomed Chromatogr, 2013 Jul;27(7):859-65.
    PMID: 23386533 DOI: 10.1002/bmc.2872
    In this study, a simple and reliable reverse-phase high-performance liquid chromatography (RP-HPLC) method was established and validated to analyze S-mephenytoin 4-hydroxylase activity of a recombinant CYP2C19 system. This system was obtained by co-expressing CYP2C19 and NADPH-CYP oxidoreductase (OxR) proteins in Escherichia coli (E. coli) cells. In addition to RP-HPLC, the expressed proteins were evaluated by immunoblotting and reduced CO difference spectral scanning. The RP-HPLC assay showed good linearity (r(2) = 1.00) with 4-hydroxymephenytoin concentration from 0.100 to 50.0 μm and the limit of detection was 5.00 × 10(-2) μm. Intraday and interday precisions determined were from 1.90 to 8.19% and from 2.20 to 14.9%, respectively. Recovery and accuracy of the assay were from 83.5 to 85.8% and from 95.0 to 105%. Enzyme kinetic parameters (Km , Vmax and Ki ) were comparable to reported values. The presence of CYP2C19 in bacterial membranes was confirmed by immunoblotting and the characteristic absorbance peak at 450 nm was determined in the reduced CO difference spectral assay. Moreover, the activity level of co-expressed OxR was found to be comparable to that of the literature. As a conclusion, the procedures described here have generated catalytically active CYP2C19 and the RP-HPLC assay developed is able to serve as CYP2C19 activity marker for pharmacokinetic drug interaction study in vitro.
    Matched MeSH terms: Recombinant Proteins/chemistry
  17. Expression and characterization of a cellobiohydrolase (CBH7B) from the thermophilic fungus Thielavia terrestris in Pichia pastoris
    Woon JS, Mackeen MM, Mahadi NM, Illias RM, Abdul Murad AM, Abu Bakar FD
    Biotechnol Appl Biochem, 2016 Sep;63(5):690-698.
    PMID: 26265428 DOI: 10.1002/bab.1431
    The gene encoding a cellobiohydrolase 7B (CBH7B) of the thermophilic fungus Thielavia terrestris was identified, subcloned, and expressed in Pichia pastoris. CBH7B encoded 455 amino acid residues with a molecular mass of 51.8 kDa. Domain analysis indicated that CBH7B contains a family 7 glycosyl hydrolase catalytic core but lacks a carbohydrate-binding module. Purified CBH7B exhibited optimum catalytic activity at pH 5.0 and 55 °C with 4-methylumbelliferryl-cellobioside as the substrate and retained 85% of its activity following 24 H incubation at 50 °C. Despite the lack of activity toward microcrystalline substrates, this enzyme worked synergistically with the commercial enzyme cocktail Cellic(®) CTec2 to enhance saccharification by 39% when added to a reaction mixture containing 0.25% alkaline pretreated oil palm empty fruit bunch (OPEFB). Attenuated total reflectance Fourier transform infrared spectroscopy suggested a reduction of lignin and crystalline cellulose in OPEFB samples supplemented with CBH7B. Scanning electron microscopy revealed greater destruction extent of OPEFB strands in samples supplemented with CBH7B as compared with the nonsupplemented control. Therefore, CBH7B has the potential to complement commercial enzymes in hydrolyzing lignocellulosic biomass.
    Matched MeSH terms: Recombinant Proteins/chemistry
  18. Isolation and characterization of cDNA clones encoding ADP-glucose pyrophosphorylase from sago palm (Metroxylon sagu)
    Au SL, Tan SH, Harikrishna K, Napis S
    J. Biochem. Mol. Biol. Biophys., 2002 Oct;6(5):301-8.
    PMID: 12385964
    Four ADP-glucose pyrophosphorylase cDNA clones were isolated from mature leaves and pith of sago palm by the polymerase chain reaction (PCR) technique. Three of them (agpp10, agpp12 and agpl19) encoded the AGP large subunit, while the fourth clone (agpl1) encoded the small subunit. agpp10 and agpp12 were isolated from pith, agpl19 was isolated from mature leaves, while agpl1 from both tissues. In addition, a full-length cDNA of agpl1 was successfully isolated from a cDNA library of mature leaves by a PCR-based screening technique. Semi-quantitative analysis suggests that agpp10 and agpp12 were detectable only in pith, agpl19 only in leaves, while agpl1 was expressed in both leaves and pith tissues.
    Matched MeSH terms: Recombinant Proteins/chemistry
  19. Cloning and expression of the phosphoprotein gene of Newcastle disease virus in Escherichia coli
    Kho CL, Tan WS, Yusoff K
    J. Biochem. Mol. Biol. Biophys., 2002 Apr;6(2):117-21.
    PMID: 12186767
    The phosphoprotein (P) gene of a heat stable Newcastle disease virus (NDV) was cloned, sequenced and expressed in Escherichia coli. SDS-PAGE analysis of the recombinant P protein (395 amino acids) and a C-terminal extension derivative (424 amino acids), gave rise to two distinct protein bands with molecular masses of approximately 53-55 and 56-58 kDa, respectively, which are approximately 26-30% heavier than those calculated from the deduced amino acid sequences. The differences in molecular mass on SDS-PAGE are thought to be attributed to the acidic nature of the P protein (pI=6.27) and also the different degrees of phosphorylation in the prokaryotic cell. Amino acid sequence comparison of the P protein among the published NDV strains showed that they were highly conserved particularly at the putative phosphorylation sites.
    Matched MeSH terms: Recombinant Proteins/chemistry
  20. Solubility, immunogenicity and physical properties of the nucleocapsid protein of Nipah virus produced in Escherichia coli
    Tan WS, Ong ST, Eshaghi M, Foo SS, Yusoff K
    J Med Virol, 2004 May;73(1):105-12.
    PMID: 15042656
    The nucleocapsid (N) protein of Nipah virus (NiV) can be produced in three Escherichia coli strains [TOP10, BL21(DE3) and SG935] under the control of trc promoter. However, most of the product existed in the form of insoluble inclusion bodies. There was no improvement in the solubility of the product when this protein was placed under the control of T7 promoter. However, the solubility of the N protein was significantly improved by lowering the growth temperature of E. coli BL21(DE3) cell cultures. Solubility analysis of N- and C-terminally deleted mutants revealed that the full-length N protein has the highest solubility. The soluble N protein could be purified efficiently by sucrose gradient centrifugation and nickel affinity chromatography. Electron microscopic analysis of the purified product revealed that the N protein assembled into herringbone-like particles of different lengths. The C-terminal end of the N protein contains the major antigenic region when probed with antisera from humans and pigs infected naturally.
    Matched MeSH terms: Recombinant Proteins/chemistry
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