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1.
Jiaxin Zhang Ali Movahedi Zhiheng Wei Ming Sang Xiaolong Wu Mengyang WangHui Wei Huixin PanTongming Yin Qiang Zhuge 《Analytical biochemistry》2016
The antimicrobial peptide ABP-dHC-cecropin A is a small cationic peptide with potent activity against a wide range of bacterial species. Evidence of antifungal activity has also been suggested; however, evaluation of this peptide has been limited due to the low expression of cecropin proteins in Escherichia coli. To improve the expression level of ABP-dHC-cecropin A in E. coli, tandem repeats of the ABP-dHC-cecropin A gene were constructed and expressed as fusion proteins (SUMO-nABP-dHC-cecropin, n = 1, 2, 3, 4) via pSUMO-nABP-dHC-cecropin A vectors (n = 1, 2, 3, 4). Comparison of the expression levels of soluble SUMO-nABP-dHC-cecropin A fusion proteins (n = 1, 2, 3, 4) suggested that BL21 (DE3)/pSUMO-3ABP-dHC-cecropin A is an ideal recombinant strain for ABP-dHC-cecropin A production. Under the selected conditions of cultivation and isopropylthiogalactoside (IPTG) induction, the expression level of ABP-dHC-cecropin A was as high as 65 mg/L, with ∼21.3% of the fusion protein in soluble form. By large-scale fermentation, protein production reached nearly 300 mg/L, which is the highest yield of ABP-dHC-cecropin A reported to date. In antibacterial experiments, the efficacy was approximately the same as that of synthetic ABP-dHC-cecropin A. This method provides a novel and effective means of producing large amounts of ABP-dHC-cecropin A. 相似文献
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A hidden aggregation‐prone structure in the heart of hypoxia inducible factor prolyl hydroxylase
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Hamid Hadi‐Alijanvand Elizabeth A. Proctor Feng Ding Nikolay V. Dokholyan Ali A. Moosavi‐Movahedi 《Proteins》2016,84(5):611-623
Prolyl hydroxylase domain‐containing protein 2 (PHD2), as one of the most important regulators of angiogenesis and metastasis of cancer cells, is a promising target for cancer therapy drug design. Progressive studies imply that abnormality in PHD2 function may be due to misfolding. Therefore, study of the PHD2 unfolding pathway paves the way for a better understanding of the influence of PHD2 mutations and cancer cell metabolites on the protein folding pathway. We study the unfolding of the PHD2 catalytic domain using differential scanning calorimetry (DSC), fluorescence spectroscopy, and discrete molecular dynamics simulations (DMD). Using computational and experimental techniques, we find that PHD2 undergoes four transitions along the thermal unfolding pathway. To illustrate PHD2 unfolding events in atomic detail, we utilize DMD simulations. Analysis of computational results indicates an intermediate species in the PHD2 unfolding pathway that may enhance aggregation propensity, explaining mutation‐independent PHD2 malfunction. Proteins 2016; 84:611–623. © 2016 Wiley Periodicals, Inc. 相似文献
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Poddar NK Ansari ZA Singh RK Moosavi Movahedi AA Ahmad F 《Journal of biomolecular structure & dynamics》2010,28(3):331-341
Experimental results of RNase-A stabilization by sugar osmolytes show that the change in the Gibbs free energy (ΔGD) associated with the equilibrium, N (native) state ? D (denatured) state of the protein in the presence of equimolar mixture of monosaccharides is larger than that of the corresponding oligosaccharides at a given temperature and pH. However, at the molar scale, ΔGD obtained in the presence of an oligosaccharide is much higher as compared with ΔGD obtained using individual monosaccharide. We used scaled particle theory (SPT) to explain these experimental observations. The effective length, called Tolman's length that describes the curvature correlations to a surface area or surface tension and in turn contributes to the change in free energy, is discussed. Tolman's length is higher for corresponding monomer mixture than the oligosaccharide molecules. Based on SPT analysis, a geometrical model is proposed for clustering of monosaccharides in the mixture due to high particle density. The cluster is presumed to have weak interaction among them due to larger hydrodynamic radius than that of the bonded molecules of oligosaccharides. 相似文献
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Effect of neohesperidin dihydrochalcone on the activity and stability of alpha‐amylase: a comparative study on bacterial,fungal, and mammalian enzymes
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Elaheh Kashani‐Amin Azadeh Ebrahim‐Habibi Bagher Larijani Ali Akbar Moosavi‐Movahedi 《Journal of molecular recognition : JMR》2015,28(10):605-613
Neohesperidin dihydrochalcone (NHDC) was recently introduced as an activator of mammalian alpha‐amylase. In the current study, the effect of NHDC has been investigated on bacterial and fungal alpha‐amylases. Enzyme assays and kinetic analysis demonstrated the capability of NHDC to significantly activate both tested alpha‐amylases. The ligand activation pattern was found to be more similar between the fungal and mammalian enzyme in comparison with the bacterial one. Further, thermostability experiments indicated a stability increase in the presence of NHDC for the bacterial enzyme. In silico (docking) test locates a putative binding site for NHDC on alpha‐amylase surface in domain B. This domain shows differences in various alpha‐amylase types, and the different behavior of the ligand toward the studied enzymes may be attributed to this fact. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Nanocrystalline mixed metal oxides (MMO) of various metal cations were synthesized and were used for coating a piece of copper wire as a new high sensitive solid phase micro extraction (SPME) fiber in extraction and determination of BTEX compounds from the headspace of aqueous samples prior to GC-FID analysis. Under optimum extraction conditions, the proposed fiber exhibited low detection limits, and quantification limits, good reproducibility, simple and fast preparation method, high fiber capacity and high thermal and mechanical durability. These are some of the most important advantages of the new fiber. The proposed fiber was used for human hemoglobin upon interaction with benzene. Binding isotherm, Scatchard and Klotz logarithmic plots were constructed using HS-SPME-GC data, accurately. The obtained binding isotherm analyzed using Hill method. The Hill parameters have been obtained by calculating saturation parameter from the ratio of measured chromatographic peak areas in the presence and absence of hemoglobin. In this interaction, Hill coefficient and Hill constant determined as (nH = 6.14 and log KH = 6.47) respectively. These results reveal the cooperativity of hemoglobin upon interaction with benzene. 相似文献
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Bijan Keikhaei Pejman Salehi-Fard Mostafa Paridar Mehraneh Karimzadeh Razie Dehghani Asma Zamiri Vahideh Takhviji 《生物学前沿》2018,13(6):469-474
Background
Thalassemia is known as the commonest monogenic disorder with an imbalanced rate of globin chains production of adult hemoglobin. Despite the available information about the thalassemia etiology, its phenotype varies from each patient to another. This study aimed to evaluate the hematological parameters of patients with the same -α3.7 homozygote and heterozygote genotypes to amend screening programs.Methods
In this observational study, we evaluated 1301 thalassemia suspected patients who referred to the Thalassemia and Hemoglobinopathy Research Center of Ahvaz University of Medical Sciences, Khuzestan, Iran during 2014–2016. According to the genotyping studies, patients divided into 2 groups with -α3.7/αα (n = 646) and -α3.7/-α3.7 (n = 181) genotypes. Thereafter, distribution of hematological parameters evaluated in both groups.Results
The mean age in heterozygous and homozygous groups was 25.7±4.5 and 26±4.4 years old, respectively. The degree of anemia was considerably varied in patients with the same genotype. MCV, RBC and MCH showed a wide distribution in patients.Conclusion
The findings presented here suggest that other molecular mechanisms along with α-globin gene mutations could be involved in determining the phenotypes of alpha thalassemia patients.10.
Seyed Jafar Mousavy Gholam Hossein Riazi Mahmood Kamarei Hadi Aliakbarian Naghmeh Sattarahmady Ahmad Sharifizadeh Shahrokh Safarian Faizan Ahmad Ali Akbar Moosavi–Movahedi 《International journal of biological macromolecules》2009,44(3):278-285
Widespread use of mobile phones has increased the human exposure to electromagnetic fields (EMFs). It is required to investigate the effect of EMFs on the biological systems. In this paper the effect of mobile phone RF (910 MHz and 940 MHz) on structure and function of HbA was investigated. Oxygen affinity was measured by sodium dithionite with UV–vis spectrophotometer. Structural changes were studied by circular dichroism and fluorescence spectroscopy. The results indicated that mobile phone EMFs altered oxygen affinity and tertiary structure of HbA. Furthermore, the decrease of oxygen affinity of HbA corresponded to the EMFs intensity and time of exposure. 相似文献