Iranian Biomedical Journal (2008823X)7(3)pp. 145-145
Iranian Journal Of Public Health (22516085)33(2)pp. 56-59
Fibrillin is a large glycoprotein synthesized in the tissues involved in Marfan syndrome, and known to be involved in tissue elasticity. The syndrome is corresponded to fbn1 gene and is characterized by cardiovascular, ocular, and skeletal abnormalities. N-terminus of fibrillin 1 binds to microfibril-associated glycoprotein 1 (MAGP-1) in a calcium-dependent manner. In this study, the amino acid sequence of fibrillin protein of a patient with Marfan syndrome (accession No. XM- 034890) has been compared to the amino acid sequence of normal fibrillin (accession No. P-35555). In this patient, mutations causing a Gly (267) to Thr and Tyr (532) to Cys amino acids changes have been occurred. Method of Garnier was used to predict the secondary structure of the proteins and probable N-glycosylation sites were searched. Results of these analyses show no significant structural difference between the mutant and normal fibrillin proteins. Although in some cases characterization of the binding requirements has shown that a folded, secondary structure of fibrillin was necessary for binding, our results are in agreement with those findings that at least in some cases, fibrillin gene defects are not sole determinants of Marfan phenotype. © 2004, Iranian Journal of Public Health. All rights reserved.
Burns (03054179)30(8)pp. 829-832
Masjid-i-Sulaiman (MIS) is located in the southwest of Iran. Unfortunately, some parts of MIS are contaminated by subsurface leakage of natural gas containing H 2S. In order to investigate the possible effect(s) of chronic exposure to sulfur compounds on suicidal behavior, the present study was done. In the 2-year period, 561 individuals attempted suicide (260 men and 301 women). Completed suicide comprised of 19 men and 32 women. The rate per 100,000 person-years was 19.9 for men and 34.8 for women aged over 15 years. Forty-two (13 men and 29 women) of 561 patients were self-immolators by fire with a male:female ratio 0.45. This represents 22.4 burns per 100,000 person-years and is equivalent to 7.4% of all suicide attempts. Thirty-three of 42 patients died (78.6%) who were 9 men and 24 women with male:female ratio 0.37. There is statistically significant differences between sex groups (P (2) = 0.0091). The self-inflicted burn was the most frequent method for lethal suicide. Winter was the most common season for self-burning followed by spring. Statistical analysis showed significant difference between seasons for self-inflicted burn (P (2) = 0.00001). Analysis of correlation showed statistically positive correlation coefficient between mean values of all reactive sulfur compounds and seasonal frequency of suicide (r = 0.923, P (1) = 0.038). © 2004 Elsevier Ltd and ISBI. All rights reserved.
Biochemical and Biophysical Research Communications (0006291X)316(3)pp. 749-752
In order to find the effect of genetic polymorphisms of GSTM1 and GSTT1 on blood pressure of individuals chronically exposed to sulfur compounds, the present study was done. Study subjects (38 males, 38 females) were residents of contaminated areas of Masjid-i-Sulaiman (southwest of Iran). The GSTM1 and GSTT1 genotypes were determined using a polymerase chain reaction (PCR)-based method. The non-parametric Sign test was applied in order to detect differences between the GSTs genotypes of study subjects and the normal mean values according to the sex and age of subjects. From four combination of genotypes, systolic blood pressure significantly decreased in combination of null-GSTM1 and present-GSTT1 (Z=-2.41; P=0.016), and diastolic blood pressure significantly increased in combination of present-GSTM1 and null-GSTT1 (Z=+2. 14; P=0.032). It is speculated about polymorphisms of GSTs in individuals chronically exposed to natural sour gas, which contains H2S, fulfilling a physiological role(s) in regulating blood pressure. © 2004 Elsevier Inc. All rights reserved.
Pharmacology Biochemistry and Behavior (00913057)77(4)pp. 793-795
To identify whether the polymorphisms of glutathione S-transferase M1 (GSTM1) and GSTT1 genes predict a high-tended risk of using tobacco, the GSTM1 and GSTT1 genotypes of 369 Iranian males (254 nonsmokers and 115 smokers) and 314 Iranian females (245 nonsmokers and 69 smokers) were determined. The frequencies of GSTM1 (males: OR=0.98, 95% CI=0.62-1.57, P=.974; females: OR=1.34, 95% CI=0.75-2.39, P=.358) and GSTT1 (males: OR=1.25, 95% CI=0.76-2.04, P=.412; females: OR=0.84, 95% CI=0.46-1.51, P=.626) null genotypes were similar in nonsmokers and smokers. The risk of being a smoker was to be equally frequent in each combination of the genotypes. The present results revealed that there was no difference between smokers and nonsmokers for these two genetic polymorphisms. © 2004 Elsevier Inc. All rights reserved.
Brazilian Journal of Medical and Biological Research (0100879X)37(5)pp. 675-681
We describe the impact of subtype differences on the seroreactivity of linear antigenic epitopes in envelope glycoprotein of HIV-1 isolates from different geographical locations. By computer analysis, we predicted potential antigenic sites of envelope glycoprotein (gp120 and gp41) of this virus. For this purpose, after fetching sequences of proteins of interest from data banks, values of hydrophilicity, flexibility, accessibility, inverted hydrophobicity, and secondary structure were considered. We identified several potential antigenic epitopes in a B subtype strain of envelope glycoprotein of HIV-1 (IIIB). Solid-phase peptide synthesis methods of Merrifield and Fmoc chemistry were used for synthesizing peptides. These synthetic peptides corresponded mainly to the C2, V3 and CD4 binding sites of gp120 and some parts of the ectodomain of gp41. The reactivity of these peptides was tested by ELISA against different HIV-1-positive sera from different locations in India. For two of these predicted epitopes, the corresponding Indian consensus sequences (LAIERYLKQQLLGWG and DIIGDIRQAHCNISEDKWNET) (subtype C) were also synthesized and their reactivity was tested by ELISA. These peptides also distinguished HIV-1-positive sera of Indians with C subtype infections from sera from HIV-negative subjects.
Khalafi-nezhad, A.,
Rad, M.N.S.,
Mohabatkar, H.,
Asrari z., ,
Hemmateenejad b., Bioorganic and Medicinal Chemistry (14643391)13(6)pp. 1931-1938
In view of obtaining some potential antibacterial compounds, we have described synthesis of some chloroaryloxyalkyl imidazole and benzimidazole derivatives. The relevant step in the synthetic sequence was the initial condensation of 4-chloro or 2,4-dichlorophenol with 1, n-dibromoalkanes (n = 2, 4, 5) to provide compounds 3a-f in sufficient yields. The subsequent condensation of 3a-f with some imidazole derivatives and benzimidazole afforded products 4a-l and 5a-e in good yields. Some of compounds 4a-l as well as 5a-e were tested in vitro against Salmonella typhi O-901 and Staphylococcus aureus A 15091. Compounds 4a and 4c showed considerable bactericidal activities against tested bacteria. Compound 4b showed significant activity against S. aureus A 15091 but was inactive against S. typhi O-901. Other compounds showed intermediate activities against S. aureus A 15091 but most of them were inactive against S. typhi O-901. Semiempirical AM1 calculations showed that negative electrostatic potentials around oxygen of the phenoxy and nitrogen of the imidazole moieties have direct effect on the antibacterial activity towards S. aureus A 15091. In QSAR analysis, different electronic, topologic, functional groups and physicochemical descriptors were calculated for each molecule and a three parametric equation was found between the log MIC and HOMO energy, hydration energy and number of primary carbon atoms of the molecules. © 2005 Elsevier Ltd. All rights reserved.
Iranian Biomedical Journal (2008823X)9(1)pp. 37-40
This study was conducted to determine the location of DNA segment with homology to the rat conserved genomic DNA in human chromosomes. The labeled rat genomic DNA was hybridized with normal human (male) metaphases. The study of 74 metaphases after fluorescence in situ hybridization showed 371 twin-spot signals on human chromosomes. Statistical analysis indicated that the specific accumulation of signals on 1q22-qter, 2p2, 3p21-p23, 4q3, 6q2, 8p12-pter, 11p12-pter, 11q12-qter, 12q2, 13p, 15p, 16q2, 21q12-qter, Yq1-qter, and Xq2 was not random. Results of stepwise multiple linear regressions indicated that number of mapped oncogenes (Beta = 1.092; t = 7.552; P<0.001) and density of mapped oncogenes on chromosomes (Beta = -0.832; t = -5.751; P<0.001) have significant effects on number of double-spots on human chromosomes. These data reflects the evolutionary conservation between rat DNA and human DNA at the above-mentioned bands.
Advances in Biochemical Engineering/Biotechnology (07246145)100pp. 19-51
Saving energy, cost efficiency, producing less waste, improving the biodegradability of products, potential for producing novel and complex molecules with improved properties, and reducing the dependency on fossil fuels as raw materials are the main advantages of using biotechnological processes to produce chemicals. Such processes are often referred to as green chemistry or white biotechnology. Metabolic engineering, which permits the rational design of cell factories using directed genetic modifications, is an indispensable strategy for expanding green chemistry. In this chapter, the benefits of using metabolic engineering approaches for the development of green chemistry are illustrated by the recent advances in microbial production of isoprenoids, a diverse and important group of natural compounds with numerous existing and potential commercial applications. Accumulated knowledge on the metabolic pathways leading to the synthesis of the principal precursors of isoprenoids is reviewed, and recent investigations into isoprenoid production using engineered cell factories are described. © Springer-Verlag 2005.
Saudi Medical Journal (16583175)27(8)pp. 1121-1124
Objective: Human T-cell leukemia virus type 1 (HTLV-1) is an enveloped retrovirus, which is associated with a T-cell malignancy known as adult T-cell leukemia (ATL). Variation in the HTLV-1 envelope nucleotide sequence has been extensively documented and has been used to classify HTLV-1 isolates into different subtypes. The virus occurs in at least 3 subtypes, which have been named A, B, and C. We conducted this study to compare the antigenic proprieties of the Iranian isolate of HTLV-1 with the homologous region of different subtypes of the virus. Methods: This study took place in the Department of Biology, College of Sciences, Shiraz University, Iran in 2005. The predicted antigenic sites and secondary structure of the envelope glycoprotein of HTLV-1, present in Iran, have been compared with the antigenic sites and secondary structure of the homologous domains in subtypes A, B, C of the virus. To predict the epitopes of glycoproteins, 21 different scales were used. Results: The number of helices in the Iranian isolate was equal to the number of these regions in all 3 subtypes, but the number of β-sheets was more than other viruses. One potential glycosylation site, on all these studied envelope glycoproteins, was predicted. Antigenic sites in the Iranian isolate were almost similar to subtype A of the virus and the Iranian isolate of HTLV-1 may be belongs to subtype A. Conclusion: Our results indicate the similarities and differences between the Iranian and other subtypes of HTLV-1. Antigenic sites represent potential candidates for use in a peptide vaccine against HTLV-1 glycoproteins and since most of the properties of a particular protein depend on its structural properties, this type of study can help in better understanding of HTLV-1 isolates present in Iran.
Colloids and Surfaces B: Biointerfaces (09277765)55(1)pp. 84-89
Human serum albumin (HSA) is frequently used in biophysical and biochemical studies since it has a well-known primary structure and it has been associated with the binding of many different categories of small molecules. In the present study, results are presented for the binding of cetylpyridinium chloride (CPC) with HSA at various pH and 25 °C, as monitored using ion selective membrane electrodes and fluorescence spectroscopy of intrinsic tryptophan. The obtained binding isotherms were analyzed on basis of binding capacity concept and Hill plot in order to determine the Hill parameters of binding sets. The system behaved as a system with two sets of binding sites in all studied situations. The results represent a positive cooperative behavior and the essential role of hydrophobic interactions in both binding sets. The intrinsic binding affinity of second binding set have a similar values and trends at acidic and neutral pHs, that represents the similar unfolded structure at these pHs. CPC quenched the fluorescence arising from Trp group incorporated to HSA. A biphasic behavior was observed in quenching process that confirmed the results of binding study correspond to the existence of two binding sets. The similarity of unfolded structure in acidic and neutral pH was also confirmed by fluorescence study. The quenching of HSA fluorescence takes place with a Stern-Volmer constant of 0.643 × 104, 1.23 × 104 and 7.40 × 104 at pH 3.5, 6.8 and 9.5, respectively. The Stern-Volmer behavior observed at low molar ratio of [CPC]/[HSA] (about 6), that represents the occurrence of conformational changes after this molar ratio. Comparing, the KSV values and binding parameters indicate that the binding is dominated by hydrophobic effects and, in minor degree, by electrostatic interactions. © 2006 Elsevier B.V. All rights reserved.
Pakistan Journal of Biological Sciences (18125735)10(23)pp. 4295-4298
In the present study, T-cell epitopes of gp120 of an Iranian isolate have been compared to different subtypes of HIV-1. At first, the amino acid sequences of gp120 were fetched from data banks. Then T-cell epitopes, disulfide bonding states, protein kinase C phosphorylation sites, cAMP-dependent protein kinase phosphorylation sites, casein kinase II phosphorylation sites, N-myristoylation sites and amidation sites were predicted using different soft wares. According to this computational analysis 6 good disulfide binding states in Iranian gp120 were predicted. From the viewpoint of cAMP-dependent protein kinase phosphorylation site (1 site) Iranian isolate was similar to clades B and F. Like subtype C 1 amidation site was predicted in the Iranian subtype. In the Iranian isolate 7 sites protein kinase C phosphorylation sites and 4 N-myristoylation sites were predicted. Since the number of individuals infected with HIV-1 in Iran, like many other countries is increasing, study of similarities and differences between the Iranian samples and different clades of HIV-1 can help us in identification of the origin and understanding the changes in the virus. © 2007 Asian Network for Scientific Information.
Nanoscale Research Letters (1556276X)2(1)pp. 24-27
Computer-aided design plays a fundamental role in both top-down and bottom-up nano-system fabrication. This paper presents a bottom-up nano-filter patterning process based on DNA self-assembly. In this study we designed a new method to construct fully designed nano-filters with the pores between 5 nm and 9 nm in diameter. Our calculations illustrated that by constructing such a nano-filter we would be able to separate many molecules.
Asian Pacific Journal of Cancer Prevention (15137368)8(4)pp. 602-606
HPV-16 is the HPV most often linked to cervical carcinoma. E6 of the HPV-16 which expressed early in cancer cells is a target for immune therapeutic methods. In the present study, after fetching the sequence of HPV-16 E6 (accession No: ABC48950) from NCBI databank, by using hydrophilicity, flexibility, accessibility, turns, exposed surface, polarity and antigenic propensity scales, B cell epitopes of the protein were predicted. In addition, MHCPred version 2.0 program was used to predict MHC Class I and Class II alleles. The sequences of the epitopes were also found out. According to this computer-based prediction the results from A0203 and DRB0101 reveal lower IC50 than other alleles. For A0203 allele, peptide with the best binding affinity was 25ELQTTIHDI33. For DRB0101 allele, the peptide was 39YCKQQLLRR47. Different structural features of the protein were also predicted. These features were including glycosylation, kinase C phosphorylation, Casein kinase II phosphorylation and N-myristylation sites, and disulfide bonding states. By using these computational scales and programs, 0 glycosylation, 3 kinase C phosphorylation, 2 casein kinase II phosphorylation and 1 Nmyristylation sites and 2 disulfide bonds were predicted. Development and approval of new vaccines are keys for control of cancer. Epitopes and structural features of proteins can be predicted and this information can help us in molecular and medical studies of viruses.
Soudmand-asli, A.,
Ayatollahi, S.,
Mohabatkar, H.,
Zareie, M.,
Shariatpanahi, S.F. Journal of Petroleum Science and Engineering (09204105)58(1-2)pp. 161-172
These experiments aim to investigate the microbial enhanced oil recovery (MEOR) technique in fractured porous media using etched-glass micromodels. Three identically patterned micromodels with different fracture angle orientation of inclined, vertical and horizontal with respect to the flow direction were utilized. A non-fractured model was also used to compare the efficiency of MEOR in fractured and non-fractured porous media. Two types of bacteria were employed: Bacillus subtilis (a biosurfactant-producing bacterium) and Leuconostoc mesenteroides (an exopolymer-producing bacterium). The results show that higher oil recovery efficiency can be achieved by using biosurfactant-producing bacterium in fractured porous media. Further investigation on the effect of the mentioned bacteria on oil viscosity, porous media permeability and wettability suggests that the plugging of matrix-fracture interfaces by an exopolymer is the main reason for the low performance of the exopolymer-producing bacterium. Oil viscosity reduction as well as the reduction of IFT was also found to be the reason for better microbial recovery efficiencies of biosurfactant-producing bacterium in the fractured models. © 2007 Elsevier B.V. All rights reserved.
Saudi Medical Journal (16583175)28(10)pp. 1520-1524
Objectives: To study primer sequences (1060, 1247, 1254, 1281, 1283, and 1290) for random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). Methods: Twenty-four clinical Serratia marcescens (S. marcescens) isolates were obtained over a 6-month period from April 2002 to September 2002 from hospitals in the Fars province of Iran. Six primers were used due to S. marcescens genome properties, and RAPD-PCR was carried out. The results were subjected to unweighted pair-group method analysis using NTSYSpc 2.02. The primers were blasted with the S. marcescens genome, and the primers efficiency was estimated. Results: The results of blast primers with S. marcescens genome sequence showed that primer 1283 had the highest homology and primer 1290 had the lowest homology. Comparing the resulted dendrograms showed that the pattern of the primers to separate isolates was closely related to their sequence homology with the genome and their amount of guanine and cytosine nucleotide content. Conclusions: There are clear differences in RAPD-PCR results when different primers are used, and it is recommended to consider genomic properties of an organism to design a primer for RAPD-PCR.
Asian Pacific Journal of Cancer Prevention (15137368)9(4)pp. 631-636
Human papillomaviruses (HPVs) are small DNA tumor viruses that replicate and assemble exclusively in the nucleus. Thus their proteins, including E6, must carry nuclear localization signals (NLSs) to enter the nucleus. To analyze and to predict the nuclear localization signals and several post translational modifications by bioinformatics analysis, we obtained 91 E6 protein sequences from available databases. To investigate the localization of these sequences, we used Hum-Ploc software. Homology and alignment of sequences were performed by Blast software and Multalin server respectively. Prediction of N-glycosylation and serine, threonine and tyrosine phosphorylation sites of HPV E6 protein sequences was accomplished with NetNGlyc and NetPhos software. Out of 91 types, the NLSs of 29 types were predicted by signal-3L and signal-CF software. We tried to predict the NLSs of remaining HPV E6 proteins according to the homology of the already predicted NLSs. However, because of considerable variation between E6 protein sequences, we could not classify the NLSs in monopartite or bipartite. According to the results, all NLSs of HPV E6 proteins could be assigned to 11 categories. NLSs of several HPV E6 protein sequences were also determined by experimental studies. Overall, different types of HPV E6 protein in same category show approximately similar pattern in post translational modifications such as N-glycosylation and phosphorylation. Some HPV "early"genes, such as E6, are known to act as oncogenes that promote tumor growth and malignant transformation. Thus more detailed recognition of nuclear localizing sequences and nucleocytoplasmic transport pathway can play a key role in prevention and treatment of HPV infection and related cancers. The results also show that bioinformatics technology can direct and simplify experimental studies.
Mohammadzadegan, R.,
Mohabatkar, H.,
Sheikhi, M.H.,
Safavi, A.,
Khajouee, M.B. Physica E: Low-Dimensional Systems and Nanostructures (13869477)41(1)pp. 142-145
We have developed simple methods of reproducibly creating deoxyribonucleic acid (DNA)-templated gold nanowires on silicon. First DNA nanowires were aligned on silicon surfaces. Briefly, modified silicon wafer was soaked in the DNA solution, and then the solution was removed using micropipettes; the surface tension at the moving air-solution interface is sufficient to align the DNA nanowires on the silicon wafer. In another attempt, an aqueous dispersion of sodium azide-stabilized gold nanoparticles was prepared. The nanoparticles aligned double-stranded λ-DNA to form a linear nanoparticle array. Continuous gold nanowires were obtained. The above nanowires were structurally characterized using scanning electron microscopy. The results of the characterizations show the wires to be 57-323 nm wide, to be continuous with a length of 2.8-9.5 μm. The use of DNA as a template for the self-assembly of conducting nanowires represents a potentially important approach in the fabrication of nanoscale interconnects. © 2008 Elsevier B.V. All rights reserved.
Journal of Applied Animal Research (09741844)34(2)pp. 179-180
Fortyfive adult male rats (220-250g) were divided into 3 equal groups. Rats of group 1 were exposed to 50Hz, 500jiT in solenoid 10 hi day for 2 mo, group 2 were kept in condition similar to the group 1 except in off solenoid and group 3 were kept in normal condition of animal room. Serum glucose of the EMF exposed group was significantly higher and their weight gain, serum insulin and cholesterol were less than those of other groups. These findings demonstrated the potential role of EMF for clinical use. © GSP, India.
Archives of Biochemistry and Biophysics (10960384)470(2)pp. 103-110
The heat capacity changes for interaction of human serum albumin (HSA) and a cationic surfactant-cetylpyridinium chloride (CPC), were studied at conditions close to physiological (50 mM HEPES or phosphate buffer, pH 7.4 and 160 mM NaCl) carrying out isothermal calorimetric titrations (ITC) at various temperatures (20-40 °C). ITC measurements indicated that the small endothermic changes associated with CPC demicellization were temperature independent at these conditions. Surprisingly, important enthalpy changes associated with binding of CPC to HSA were exothermic and temperature independent at lower concentrations (below 0.022 mM) of CPC and endothermic and temperature dependent at higher concentrations of CPC. The values of heat capacity changes were obtained for each studied concentration of CPC from the plot of enthalpy changes vs temperature. The obtained results demonstrate the temperature independence of heat capacity changes at entire range of studied CPC concentrations. Both enthalpograms and heat capacity curves indicate the two-step mechanism of HSA folding changes due to its interactions with CPC. The first step corresponds to transition from native state to partially unfolded state and the second to unfolding and to the loss of tertiary structure. The analysis of the results indicates that predominant cooperative unfolding occurs at CPC/HSA molar ratio region between 25 and 30. Such information could not be extracted from thermograms and describes the role of heat capacity as a major thermodynamic quantity giving insight on physical, mechanistic and even atomic-level into how HSA may unfold and interact with CPC. The effect of CPC binding on HSA intrinsic fluorescence, UV-Vis and CD spectra were also examined. Hence, the analysis of spectral data confirms the ITC results about the biphasic mechanism of HSA folding changes induced by CPC. The CD measurement also represents the conservation of considerable secondary structure of HSA due to interaction with CPC. © 2007 Elsevier Inc. All rights reserved.
Mansoori e.g., ,
Zolghadri m.j., ,
Katebi s.d., ,
Mohabatkar, H.,
Boostani r., ,
Sadreddini m.h., Iranian Journal Of Fuzzy Systems (17350654)5(2)pp. 21-33
This paper considers the generation of some interpretable fuzzy rules for assigning an amino acid sequence into the appropriate protein superfamily. Since the main objective of this classifier is the interpretability of rules, we have used the distribution of amino acids in the sequences of proteins as features. These features are the occurrence probabilities of six exchange groups in the sequences. To generate the fuzzy rules, we have used some modified versions of a common approach. The generated rules are simple and understandable, especially for biologists. To evaluate our fuzzy classifiers, we have used four protein superfamilies from UniProt database. Experimental results show the comprehensibility of generated fuzzy rules with comparable classification accuracy.
Biotechnology (discontinued) (1682296X)7(1)pp. 19-26
To study the genetic diversity of the melon collection at the National Plant Genetic of Iran, 35 genotypes were planted at Bu Ali Sina University Hamedan in 2004 and were evaluated with 15 micro satellite SSR markers. Micro satellite markers in the upper levels showed polymorphisms and 87% of them are polymorphic and 63 alleles have been identified. The number of effective alleles in the polymorphic loci varied from 1.25-8.19 and the mean is 2.80. The percentage of genetic loci having polymorphism is 87.67%. Cluster analysis of genotypes was divided into 5 groups wherein genotype of foreign origin has smooth skin while different groups of Iran genotype are netted. Genetic distance between Iranian and foreign is 0.98. Results obtained from this study showed the significant difference between Iranian genotypes with other genotypes. These genotypes have high diversity which could be used in breeding programs. © 2008 Asian Network for Scientific Information.
Asadollahi, M.A.,
Maury, J.,
Møller, K.,
Nielsen, K.F.,
Schalk, M.,
Clark, A.,
Nielsen, J. Biotechnology and Bioengineering (00063592)99(3)pp. 666-677
The yeast Saccharomyces cerevisiae was chosen as a microbial host for heterologous biosynthesis of three different plant sesquiterpenes, namely valencene, cubebol, and patchoulol. The volatility and low solubility of the sesquiterpenes were major practical problems for quantification of the excreted sesquiterpenes. In situ separation of sesquiterpenes in a two-phase fermentation using dodecane as the secondary phase was therefore performed in order to enable quantitative evaluation of different strains. In order to enhance the availability of the precursor for synthesis of sesquiterpenes, farnesyl diphosphate (FPP), the ERG9 gene which is responsible for conversion of FPP to squalene was downregulated by replacing the native ERG9 promoter with the regulatable MET3 promoter combined with addition of 2 mM methionine to the medium. This strategy led to a reduced ergosterol content of the cells and accumulation of FPP derived compounds like target sesquiterpenes and farnesol. Adjustment of the methionine level during fermentations prevented relieving MET3 promoter repression and resulted in further improved sesquiterpene production. Thus, the final titer of patchoulol and farnesol in the ERG9 downregulated strain reached 16.9 and 20.2 mg/L, respectively. The results obtained in this study revealed the great potential of yeast as a cell factory for production of sesquiterpenes. © 2007 Wiley Periodicals, Inc.
Maury, J.,
Asadollahi, M.A.,
Møller, K.,
Schalk, M.,
Clark, A.,
Formenti, L.R.,
Nielsen, J. FEBS Letters (00145793)582(29)pp. 4032-4038
A eukaryotic mevalonate pathway transferred and expressed in Escherichia coli, and a mammalian hydrocortisone biosynthetic pathway rebuilt in Saccharomyces cerevisiae are examples showing that transferring metabolic pathways from one organism to another can have a powerful impact on cell properties. In this study, we reconstructed the E. coli isoprenoid biosynthetic pathway in S. cerevisiae. Genes encoding the seven enzymatic steps of the pathway were cloned and expressed in S. cerevisiae. mRNA from the seven genes was detected, and the pathway was shown able to sustain growth of yeast in conditions of inhibition of its constitutive isoprenoid biosynthetic pathway. © 2008 Federation of European Biochemical Societies.
Protein And Peptide Letters (09298665)15(3)pp. 280-285
Plant profilins form a well-known panallergen family responsible for cross-sensitization between plant foods and pollens. We sought to map T and B-cell epitopes on the Iranian Crocus sativus profilin by bioinformatics tools. The predicted peptides are useful for further vaccine development. © 2008 Bentham Science Publishers Ltd.
Plant Physiology (00320889)146(2)pp. 789-799
The NADPH-dependent thioredoxin reductase (NTR)/thioredoxin (Trx) system catalyzes disulfide bond reduction in the cytoplasm and mitochondrion. Trx h is suggested to play an important role in seed development, germination, and seedling growth. Plants have multiple isoforms of Trx h and NTR; however, little is known about the roles of the individual isoforms. Trx h isoforms from barley (Hordeum vulgare) seeds (HvTrxh1 and HvTrxh2) were characterized previously. In this study, two NTR isoforms (HvNTR1 and HvNTR2) were identified, enabling comparison of gene expression, protein appearance, and interaction between individual NTR and Trx h isoforms in barley embryo and aleurone layers. Although mRNA encoding both Trx h isoforms is present in embryo and aleurone layers, the corresponding proteins differed in spatiotemporal appearance. HvNTR2, but not HvNTR1, gene expression seems to be regulated by gibberellic acid. Recombinant HvNTR1 and HvNTR2 exhibited virtually the same affinity toward HvTrxh1 and HvTrxh2, whereas HvNTR2 has slightly higher catalytic activity than HvNTR1 with both Trx h isoforms, and HvNTR1 has slightly higher catalytic activity toward HvTrxh1 than HvTrxh2. Notably, both NTRs reduced Trx h at the acidic conditions residing in the starchy endosperm during germination. Interspecies reactions between the barley proteins and Escherichia coli Trx or Arabidopsis thaliana NTR, respectively, occurred with 20- to 90-fold weaker affinity. This first investigation of regulation and interactions between members of the NTR/Trx system in barley seed tissues suggests that different isoforms are differentially regulated but may have overlapping roles, with HvNTR2 and HvTrxh1 being the predominant isoforms in the aleurone layer. © 2007 American Society of Plant Biologists.
Journal of Agricultural and Food Chemistry (00218561)56(16)pp. 7528-7534
Bovine β-lactoglobulin (β-LG) in vivo (in milks) has been found in complexes with lipids such as butyric and oleic acids. To elucidate the still unknown structure-function relationship in this protein, the structural changes of β-lactoglobulin variant A (β-LG A) in the presence of anionic surfactant such as sodium n-dodecyl sulfate (SDS) and in the presence of nonionic surfactant such as Triton X-100 have been investigated. Subsequently, the retinol binding by β-LG has been investigated in the presence of various amounts of these surfactants as its binding indicator. The results of UV-vis and fluorescence studies show a higher denaturating effect of SDS at acid pH that can be due to greater positive charges of β-LG at this pH indicating also the nonspecific hydrophobic interactions of Triton X-100 with β-LG at all studied pHs. Isothermal titration calorimetry (ITC) measurements indicate the endothermic nature of β-LG/SDS interactions and the exothermic nature of Triton X-100/β-LG interactions. The analysis of the binding data demonstrates the absence of considerable changes in retinol binding properties of β-LG in the presence of various amounts of these surfactants. This implies that surfactant binding does not change the conformation of β-LG in the regions defining the retinol-binding site. © 2008 American Chemical Society.
EXCLI Journal (16112156)8pp. 190-194
Glutathione S-transferase is a family of multifunctional detoxification enzymes which are mainly cytosolic that detoxify natural and exogenous toxic compounds by conjugation with glutathione. Glutathione, an endogenous tripeptide, is important as either a reducing agent or a nucleophilic scavenger. This molecule alleviates the chemical toxicity in plants by reaction of glutathione S-transferase, and its conjugates can be transported to vacuole or apoplast. The plant soluble glutathione S-transferases grouped today into seven distinct Phi, Tau, Zeta, Theta, lambda, dehydroascorbate reductase, and tetrachlorohydroquinone dehalogenase classes. In this study, bioinformatics analysis of glutathione S-transferase gene in barley was carried out using Tau-class of barley glutathione S-transferase sequences in NCBI GenBank and isolated sequence. DNA extraction, primer design, PCR, electrophoresis, column purifica-tion, DNA sequencing and analysis by some software led to identify new sequences of Tau-class of glutathione S-transferase from barley, which is similar to Tau GST of the diploid wheat. Comparison of the deduced amino acid sequences of the three barley GST genes showed that they have 99% identity with each other but only 45% identity with the new GST. This sequence was submitted to NCBI GenBank with FI131240 accession number.
