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311.
Relation Between Protein Synthesis and Phospholipid Synthesis and Turnover in Escherichia coli 总被引:8,自引:3,他引:5
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Turnover of phospholipids occurred continuously in a fatty acid auxotroph of Escherichia coli, but in the wild-type parent strain significant turnover occurred only under conditions where protein synthesis was inhibited but lipid synthesis continued. Both strains gave a stringent response of ribonucleic acid accumulation to amino acid starvation, but only in the wild type was lipid synthesis also inhibited. A revertant strain of the auxotroph resembled the wild type in this respect. The phospholipid that accumulates in the culture medium as a result of the lipid turnover appears to be part of a loosely bound low-density complex arising from the cell envelope. 相似文献
312.
Shaida Mahmoudi Mohamad Javad Chaichi Mojtaba Shamsipur Ome Leila Nazari Abdolraouf Samadi-Maybodi 《Luminescence》2023,38(10):1711-1719
Atropine (AT) is an anticholinergic drug. AT is abundantly in Datura plant seeds. Fe3O4@Zn/Mg MOF (Fe3O4@MOF) composite was synthesized. The compound had a high peroxidase-like activity in a chemiluminescence (CL) reaction. Addition of AT quenched CL. The linear range and limit of detection were 5–600 μg L−1 and 2 × 10−2 μg L−1. This method is fast, reversible, and selective, without biodegradability effects, high accuracy, and precision for measuring AT in the Datura plant. 相似文献
313.
Naser Ajami Anvar Soleimani Reza Jafarzadeh-Esfehani Mojtaba Hasanpour Romina Rashid Shomali Mohammad Reza Abbaszadegan 《Journal of cellular and molecular medicine》2023,27(17):2457-2466
To date more than 1000 different variants in the PAH gene have been identified in patients with phenylketonuria (PKU). In Iran, several studies have been performed to investigate the genetics bases of the PKU in different parts of the country. In this study, we have analysed and present an update of the mutational landscape of the PAH gene as well as the population genetics and frequencies of detected variants for each cohort. Published articles on PKU mutations in Iran were identified through a comprehensive PubMed, Google Scholar, Web of Science (ISI), SCOPUS, Elsevier, Wiley Online Library and SID literature search using the terms: “phenylketonuria”, “hyperphenylalaninemia”, and “PKU” in combination with “Iran”, “Iranian population”, “mutation analysis”, and “Molecular genetics”. Among the literature-related to genetics of PKU, 18 studies were on the PKU mutations. According to these studies, in different populations of Iran 1497 patients were included for mutation detection that resulted in detection of 129 different mutations. Results of genetic analysis of the different cohorts of Iranian PKU patients show that the most prevalent mutation in Iran is the pathogenic splice variant c.1066-11G > A, occurring in 19.54% of alleles in the cohort. Four other common mutations were p.Arg261Gln, p.Pro281Leu, c.168 + 5G > C and p.Arg243Ter (8.18%, 6.45%, 5.88% and 3.7%, respectively). One notable feature of the studied populations is its high rate of consanguineous marriages. Considering this feature, determining the prevalent PKU mutations could be advantageous for designing screening and diagnostic panels in Iran. 相似文献
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315.
Microbial biotransformation of steroids is not a new concept, but most studies in this field have focused on fungal and bacterial systems. Microalgae, despite their photosynthetic ability and immense biodiversity, have not received much attention in this aspect until recently. Since the publication of the first article on microalgal biotransformation of steroids about 20 years ago, there have been many reports describing different modifications, including hydroxylation, reduction, side‐chain degradation, and isomerization introduced by these microorganisms on estrane, androstane, and pregnane derivatives. On the other hand, the development of new large‐scale cultivation systems, the adaptation of existing fermentation techniques to microalgae, and the introduction of microalgal genetic manipulation methods have made these organisms promising candidates for a wide range of biotechnological processes, including biotransformations. In this review, we have summarized the steroid transformation patterns of several microalgal strains and present a perspective of the future trends in microalgal biotechnology, including the possibility of adapting relatively new techniques, such as organic media catalysis and cell immobilization, to this specific field. 相似文献
316.
Farzin L Amiri M Shams H Ahmadi Faghih MA Moassesi ME 《Biological trace element research》2008,123(1-3):14-26
Monitoring of toxic trace elements for human blood has been of interest to researchers in the fields of environmental chemistry and medical science. The amount of blood toxic elements can reflect the disease state of the person or the environment where that person resides or works. Chronic, low-level exposure to toxic metals such as lead (Pb), cadmium (Cd), and mercury (Hg) is an increasing global problem. This study focuses on obtaining the usual value of Pb, Cd, and Hg in normal human blood. These elements were determined in 61 male and 40 female volunteers resident in Tehran (Iran). The subjects were non-drug abusers and aged 6-62 years old. Procedures were developed for the collection, storage, and preanalytical treatment of samples. The lead and cadmium were determined by graphite furnace atomic absorption spectrometry, and mercury was measured by cold vapor atomic absorption spectrometry technique. The blood levels of Pb, Cd, and Hg in normal volunteers living in Tehran were 123.75 +/- 56.42, 1.82 +/- 0.67, and 8.48 +/- 4.42 microg/L. There was no significant gender-related difference in blood Cd and Hg concentrations (p < 0.06 and p < 0.41). However, the results indicated significantly higher content of Pb in blood of males compared to females (138.11 +/- 65.43 and 101.84 +/- 51.38 microg/L, respectively, p < 0.05). 相似文献
317.
Proton NMR was used as a probe to study the interaction of the Tl(+) ion with 9-18-membered macromonocyclic tri-, tetra-, and hexaamines in dimethylformamide (DMF) solution. A study of proton chemical shift of ligands as a function of Tl(+) ion to ligand mole ratio revealed that the complexation reactions occur in a stepwise manner. Formation of a 1:1 complex is followed by the addition of a second complexant molecule to form a homo-sandwich complex for triazamacrocycle ligands and a mixed ligand complex in the case of hexamethylhexacyclen (HMHCY) and 1,4,7-triazacyclononane ([9]aneN(3)). The formation constants of resulting 1:1 and 1:2 (homo and mixed ligand sandwich) complexes in DMF solution were evaluated from computer fitting of the chemical shift-mole ratio data. The mixed ligand complexes may be more stable than the parent complex in which both ligands are the same. The influence of cavity size and substitution of methyl groups on nitrogen atoms of the macrocyclic ring the stability of the resulting complexes is discussed. The geometries of the tri- and tetraazamacrocycle ligands and their Tl(+) ion complexes were optimized by an ab initio method, and the calculated binding energies of resulting complexes were compared. Both the experimental and theoretical studies revealed that, in the presence of methyl groups, the stability of triazamacrocycle complexes with Tl(+) ion was decreased. 相似文献
318.
Chitinase specific activity was measured spectrophotometrically in wheat leaf tissues during the compatible and incompatible
interactions with Puccinia striiformis f. sp. tritici, the causal agent of yellow rust disease. The wheat cultivar, Federation* 4/Kavkaz, was inoculated with virulent (134E134A+) or avirulent (4EOA+) races of P. striiformis f. sp. tritici in the first leaf stage. The results showed that chitinase activity pattern was similar in both compatible and incompatible
interactions up to 72 hrs after inoculation. However, the specific activity increased rapidly in the incompatible reaction
thereafter. In susceptible reaction, chitinase activity gradually declined after 72 hrs post-inoculation reaching a level
similar to that in the control plants two weeks after inoculation. Chitinase specific activity in resistance response was
at least three times greater than that in the susceptible reaction two weeks following the inoculation. Electrophoresis of
native polyacrylamide gel impregnated with 0.1% (w/v) glycol chitinas the substrate revealed the presence of eight chitinase
isoforms with relative electrophoretic mobility (Rm) values ranging from 0.11 to 0.64 in the resolving gel.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
319.
Greta De Filippo Alessandra Garau Abdollah Yari Mojtaba Shamsipur 《Inorganica chimica acta》2005,358(3):801-807
The reactions of Ag+ with five mixed donor phenanthroline-containing macrocycles (L1-L5) having N2S3-, N2S2O-, N2S2-, N3S2-, and N4S2-donor sets, respectively, have been studied in MeCN by spectrofluorimetric, spectrophotometric, conductometric and potentiometric methods. All ligands form 1:1 [Ag(L)]+ complexes, and in the case of L4 and L5, formation of 1:2 [Ag(L)2]+ species is also observed. The corresponding formation constants have been evaluated and their values allow a deeper insight into the role played by complexation process in the potentiometric selectivity for Ag+ of membrane electrodes (ISE), and in the selective transport of Ag+ through supported liquid membrane (SLM) systems based on these ligands. The X-ray crystal structure of the complex [Ag(L4)]BF4 is also reported. 相似文献
320.