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81.
Rezaei-Ghaleh N Ramshini H Ebrahim-Habibi A Moosavi-Movahedi AA Nemat-Gorgani M 《Biophysical chemistry》2008,132(1):23-32
We have recently reported that electrostatic interactions may play a critical role in alcohol-induced aggregation of alpha-chymotrypsin (CT). In the present study, we have investigated the heat-induced aggregation of this protein. Thermal aggregation of CT obeyed a characteristic pattern, with a clear lag phase followed by a sharp rise in turbidity. Intrinsic and ANS fluorescence studies, together with fluorescence quenching by acrylamide, suggested that the hydrophobic patches are more exposed in the denatured conformation. Typical chaperone-like proteins, including alpha- and beta-caseins and alpha-crystalline could inhibit thermal aggregation of CT, and their inhibitory effect was nearly pH-independent (within the pH range of 7-9). This was partially counteracted by alpha-, beta- and especially gamma-cyclodextrins, suggesting that hydrophobic interactions may play a major role. Loss of thermal aggregation at extreme acidic and basic conditions, combined with changes in net charge/pH profile of aggregation upon chemical modification of lysine residues are taken to support concomitant involvement of electrostatic interactions. 相似文献
82.
Evaluation of inhibitory effect and apoptosis induction of Zyzyphus Jujube on tumor cell lines,an in vitro preliminary study 总被引:3,自引:0,他引:3
In the present study, water extract of dried fruit of Zyzyphus Jujube was tested for its possible anticancer effect and induction
of apoptosis on human tumor cell lines, HEp-2, HeLa and Jurkat cell lines. The inhibitory effect of water extract of this
fruit on cell proliferation was assessed by MTT colorimetric assay. The induction of apoptosis of this extract was analyzed
by DNA fragmentation analysis. Zyzyphus Jujube extract showed inhibitory effects on mentioned cell lines. Jurkat leukemic
line was found the most sensitive cells with IC50 of 0.1 μg mL−1. Our study also showed a typical DNA laddering in this cell line. The present study showed cytotoxic activity of Zyzyphus
Jujube on tumor cells. Although Zyzyphus Jujube has useful compounds for medical applications. 相似文献
83.
Bigdeli S Talasaz AH Ståhl P Persson HH Ronaghi M Davis RW Nemat-Gorgani M 《Biotechnology and bioengineering》2008,100(1):19-27
The present study reports on the retention of conformational flexibility of a model allosteric protein upon immobilization on self-assembled monolayers (SAMs) on gold. Organothiolated SAMs of different compositions were utilized for adsorptive and covalent attachment of bovine liver glutamate dehydrogenase (GDH), a well-characterized allosteric enzyme. Sensitive fluorimetric assays were developed to determine immobilization capacity, specific activity, and allosteric properties of the immobilized preparations as well as the potential for repeated use and continuous catalytic transformations. The allosteric response of the free and immobilized forms towards ADP, L-leucine and high concentrations of NAD(+), some of the well-known activators for this enzyme, were determined and compared. The enzyme immobilized by adsorption or chemical binding responded similarly to the activators with a greater degree of activation, as compared to the free form. Also loss of activity involving the two immobilization procedures were similar, suggesting that residues essential for catalytic activity or allosteric properties of GDH remained unchanged in the course of chemical modification. A recently established method was used to predict GDH orientation upon immobilization, which was found to explain some of the experimental results presented. The general significance of these observations in connection with retention of native properties of protein structures upon immobilization on SAMs is discussed. 相似文献
84.
Mojtaba Tabatabaei Yazdi Younes Ghasemi Abdollah Ghasemian Shadman Shokravi Hossein Niknahad Mohsen Amini Ali Dehshahri Mohammad Ali Faramarzi 《World journal of microbiology & biotechnology》2005,21(6-7):811-814
Summary The bioconversion of hydrocortisone by a locally isolated strain of cyanobacterium Fischerella ambigua PTCC 1635 was investigated. Fischerella ambigua had not been previously examined for this potential. The fermentation led to production of 11β,17α, 20β, 21-tetrahydroxypregn-4-en-3-one and 11β-hydroxyandrost-4-en-3,17-dione. The metabolites were isolated and purified by chromatographic methods and identified using
instrumental analyses. 相似文献
85.
Summary At high salinities and high temperatures, the growth rate of Pterocladia was high, the tips of branch initials were dilated and holdfasts broadened. By the end of the fourth week bleaching of the whole plant was complete.Under low salinities and low temperatures, the rate of vegetative growth was decreased, the cuticle was thin and food reserve was centrally accumulated in the cells.Under high salinities and low temperatures, the rate of growth was greatly reduced and cells were devoid of food reserve. Defoliation of lateral branches was frequent.Under low salinities and high temperatures, the rate of growht was rather high and cells were relatively large. 相似文献
86.
Javad Zamani Mohammad Ali Hajabbasi Mohammad Reza Mosaddeghi Mohsen Soleimani Mehran Shirvani Rainer Schulin 《Soil & Sediment Contamination》2018,27(1):13-30
Plant-based methods such as rhizodegradation are very promising for the remediation of petroleum-contaminated soils. Associations of plants with endophytes can further enhance their phytoremediation potential. In this study, a rhizobox experiment was conducted to investigate whether inoculation with the root-colonizing fungus Piriformospora indica could further enhance the degradation of petroleum hydrocarbons in the root zone of maize (Zea mays L.). The rhizoboxes were subdivided into compartments in accordance with distance from the plants. After filling the boxes with soil from a petroleum-contaminated site, seedlings that had either been inoculated with P. indica or not were grown in the middle compartments of the rhizoboxes and grown for 64 days. A plant-free treatment was included for control. The presence of roots strongly increased the counts of total and petroleum-degrading soil bacteria, respiration, dehydrogenase activity, water-soluble phenols and petroleum degradation. All these effects were also found in the soil adjacent to the middle compartments of the rhizoboxes, but strongly decreased further away from it. Inoculation with P. indica further enhanced all the recorded parameters without changing the spatial pattern of the effects. Inoculated plants also produced around 40% more root and shoot biomass than noninoculated plants and had greener leaves. Together, the results indicate that the treatment effects on the recorded soil microbial and biochemical parameters including petroleum hydrocarbon degradation were primarily due to increased root exudation. Irrespectively of this, they show that maize can be used to accelerate the rhizodegradation of petroleum hydrocarbons in soil and that inoculation with P. indica can substantially enhance the phytoremediation performance of maize. 相似文献
87.
Mohsen Hesami Mohammad Hosein Daneshvar Mohsen Yoosefzadeh-Najafabadi Milad Alizadeh 《Journal of Genetic Engineering and Biotechnology》2018,16(1):175-180
Ficus religiosa is known as a long-lived multipurpose forest tree. The tree plays an important role for religious, medicinal, and ornamental purposes. However, the propagation rate of Ficus religiosa is low in natural habitat so the plant tissue culture techniques are an applicable method for multiplication of this valuable medicinal plants. Thus, the aim of this study is to understand the effect of different auxin/cytokinin ratios on indirect shoot organogenesis of this plant. According to our results, the maximum callus induction frequency (100%) was obtained on Murashige and Skoog (MS) medium supplemented with 0.5?mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) plus 0.05?mg/l 6-benzylaminopurine (BAP) from petiole segments. For shoot induction purpose, the yellow-brownish, friable, organogenic calli were inoculated on shoot induction medium. On MS medium supplemented with 1.5?mg/l BAP and 0.15?mg/l Indole-3-butyric acid (IBA), 96.66% of the petiole-derived calli responded with an average number of 3.56 shoots per culture. The highest root formation frequency (96.66%), root number (5.5), and root length (4.83?cm) were achieved on MS medium containing 2.0?mg/l IBA plus 0.1?mg/l Naphthaleneacetic acid (NAA). The rooted shoots were successfully transferred to field condition and the substrate with the mixture of cocopeat and perlite (1:1) had the highest survival rate (96.66%). This is the first report of an effective in vitro organogenesis protocol for F. religiosa by indirect shoot organogenesis through axenic seedling derived petiole explants, which can be efficiently employed for conservation of this important medicinal plant species as well as the utilization of active biomolecules. 相似文献
88.
Arshid Yousefi-Avarvand Mohsen Tafaghodi Saman Soleimanpour Farzad Khademi 《生物学前沿》2018,13(4):293-296
Background
Tuberculosis (TB) is a contagious infectious disease caused by Mycobacterium tuberculosis (Mtb). This disease with two million deaths per year has the highest mortality rate among bacterial infections. The only available vaccine against TB is BCG vaccine. BCG is an effective vaccine against TB in childhood, however, due to some limitations, has not proper efficiency in adults. Also, BCG cannot produce an adequately protective response against reactivation of latent infections.Objective
In the present study we will review the most recent findings about contribution of HspX protein in the vaccines against tuberculosis.Methods
Therefore, many attempts have been made to improve BCG or to find its replacement. Most of the subunit vaccines for TB in various phases of clinical trials were constructed as prophylactic vaccines using Mtb proteins expressed in the replicating stage. These vaccines might prevent active TB but not reactivation of latent tuberculosis infection (LTBI). A literature search was performed on various online databases (PubMed, Scopus, and Google Scholar) regarding the roles of HspX protein in tuberculosis vaccines.Results
Ideal subunit post-exposure vaccines should target all forms of TB infection, including active symptomatic and dormant (latent) asymptomatic forms. Among these subunit vaccines, HspX is the most important latent phase antigen of M. tuberculosis with a strong immunological response. There are many studies that have evaluated the immunogenicity of this protein to improve TB vaccine.Conclusion
According to the studies, HspX protein is a good candidate for development of subunit vaccines against TB infection.89.
Moslemi Mohsen Homaei Ahmad Toiserkani Hojjat 《Bioprocess and biosystems engineering》2018,41(6):749-756
Bioprocess and Biosystems Engineering - In this study, we synthesized super magnetic Fe(OH)3@Fe3O4 nanoparticles (SPIONs) by the co-precipitation method and introduction of amine groups via... 相似文献
90.
Mohsen Mohammadi Behrouz Taheri Niloofar Momenzadeh Reza Salarinia Iraj Nabipour Zahra Farshadzadeh Afshar Bargahi 《Marine biotechnology (New York, N.Y.)》2018,20(6):718-728
Antimicrobial peptides (AMPs) have attracted attentions as a novel antimicrobial agent because of their unique activity against microbes. In the present study, we described a new, previously unreported AMP, moronecidin-like peptide, from Hippocampus comes and compared its antimicrobial activity with moronecidin from hybrid striped bass. Antibacterial assay indicated that gram-positive bacteria were more sensitive to moronecidin and moronecidin-like compared with gram-negative bacteria. Furthermore, both AMPs were found to exhibit effective antifungal activity. Comparative analysis of the antimicrobial activity revealed that moronecidin-like peptide has higher activity against Acinetobacter baumannii and Staphylococcus epidermidis relative to moronecidin. Both moronecidin-like and moronecidin peptides retained their antibacterial activity in physiological pH and salt concentration. The time-killing assay showed that the AMPs completely killed A. baumannii and S. epidermidis isolates after 1 and 5 h at five- and tenfold above their corresponding MICs, respectively. Anti-biofilm assay demonstrated that peptides were able to inhibit 50% of biofilm formation at sub-MIC of 1/8 MIC. Furthermore, moronecidin-like significantly inhibited biofilm formation more than moronecidin at 1/16 MIC. Collectively, our results revealed that antimicrobial and anti-biofilm activities of moronecidin-like are comparable to moronecidin. In addition, the hemolytic and cytotoxic activities of moronecidin-like were lower than those of moronecidin, suggesting it as a potential novel therapeutic agent, and a template to design new therapeutic AMPs. 相似文献