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1.
Yi-Hua Wu Chia-Pei Chang Chin-I Chien Yi-Kuan Tseng Chien-Chia Wang 《Molecular and cellular biology》2013,33(17):3515-3523
The yeast Saccharomyces cerevisiae possesses two distinct glycyl-tRNA synthetase (GlyRS) genes: GRS1 and GRS2. GRS1 is dually functional, encoding both cytoplasmic and mitochondrial activities, while GRS2 is dysfunctional and not required for growth. The protein products of these two genes, GlyRS1 and GlyRS2, are much alike but are distinguished by an insertion peptide of GlyRS1, which is absent from GlyRS2 and other eukaryotic homologues. We show that deletion or mutation of the insertion peptide modestly impaired the enzyme''s catalytic efficiency in vitro (with a 2- to 3-fold increase in Km and a 5- to 8-fold decrease in kcat). Consistently, GRS2 can be conveniently converted to a functional gene via codon optimization, and the insertion peptide is dispensable for protein stability and the rescue activity of GRS1 at 30°C in vivo. A phylogenetic analysis further showed that GRS1 and GRS2 are paralogues that arose from a gene duplication event relatively recently, with GRS1 being the predecessor. These results indicate that GlyRS2 is an active enzyme essentially resembling the insertion peptide-deleted form of GlyRS1. Our study suggests that the insertion peptide represents a novel auxiliary domain, which facilitates both productive docking and catalysis of cognate tRNAs. 相似文献
2.
Lucia Di Giambattista P. Grimaldi S. Gaudenzi D. Pozzi M. Grandi S. Morrone I. Silvestri A. Congiu Castellano 《European biophysics journal : EBJ》2010,39(6):929-934
We have made a preliminary analysis of the results about the effects on tumoral cell line (lymphoid T cell line Jurkat) induced
by UVB radiation (dose of 310 mJ/cm2) with and without a vegetable mixture. In the present study, we have used two techniques: Fourier transform infrared spectroscopy
(FTIR) and flow cytometry. FTIR spectroscopy has the potential to provide the identification of the vibrational modes of some
of the major compounds (lipid, proteins and nucleic acids) without being invasive in the biomaterials. The second technique
has allowed us to perform measurements of cytotoxicity and to assess the percentage of apoptosis. We already studied the induction
of apoptotic process in the same cell line by UVB radiation; in particular, we looked for correspondences and correlations
between FTIR spetroscopy and flow cytometry data finding three highly probable spectroscopic markers of apoptosis (Pozzi et
al. in Radiat Res 168:698–705, 2007). In the present work, the results have shown significant changes in the absorbance and
spectral pattern in the wavenumber protein and nucleic acids regions after the treatments. 相似文献
3.
4.
The assembly of a large physical map of genomes requires simultaneous analysis of many cosmid clones for overlapping regions. The search for overlapping regions may be achieved by various means. High-performance liquid chromatography (HPLC) provides an alternative to gel electrophoresis since microgram amounts of each DNA fragment may be collected into individual test tubes for further analysis. HPLC has been used to identify overlapping cosmid clones from a pool of cosmid DNA containing the terminal portion of the long arm of the human X chromosome (Xq24-qter). Among 400 cosmids analyzed, 3 were shown to overlap. 相似文献
5.
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7.
Lucia Lioi 《Biologia Plantarum》1987,29(1):49-53
Relationships among storage proteins in seeds from cultivars and primitive accessions of the four economically most important
species ofPhaseolus — P. vulgaris, P. coccineus, P. acutifolius andP. lunatus — were studied.
Analysis of SDS-polyacrylamide gel electrophoretic patterns of storage seed proteins revealed common characteristics in the
major groups of polypeptides forP. vulgaris, P. coccineus andP. acutifolius, while clear differences existed between thesePhaseolus species and P.lunatus. 相似文献
8.
Theory of filtration of mixed blood suspensions 总被引:1,自引:0,他引:1
A theory is developed for the flow of suspensions of blood cells through filters in which the properties of the cells are defined by statistical distributions. It is shown that conditions are generally transient, and computational procedures are developed to compute the pressure drop and the fraction of the pores of the filter containing cells of various types as a function of time. The computations show a large influence of very small concentrations of stiff cells which gradually collect in the filter and effectively plug the filter during the time of a typical test. It is also shown that the mean value of the resistance offered by a cell population with a limited distribution of resistances is more important than dispersion of resistances about the mean in determining the observable pressure curve. Experimental data are presented demonstrating that the drug pentoxifylline reduces the stiffness of leukocytes. 相似文献
9.
Bruna Tedeschi Patrizia Vernole M.Lucia Sanna Benedetto Nicoletti 《Human genetics》1992,89(5):543-547
Summary Chromosome fragile sites are inducible by aphidicolin in cultured human lymphocytes. To assess the frequency and distribution of these common fragile sites in the general population, a cytogenetic survey was performed on 126 subjects, 59 males and 67 females, whose age ranged from 1 day to 72 years. Common fragile sites, induced by aphidicolin, were widespread and showed a remarkably different sensitivity among individuals; age influenced the overall frequency of fragile sites. Moreover, both age and sex seemed to modulate the expression of specific fragile sites. In our population, the most common fragile sites were: 3p14, 16q23, Xp22, 6q26, 1p31, 4q31, 1p22, 7q22, 2q33, 3q27, 2q31, 7q32, 14q24, 10q22, 5q31, 2q37, 6p21. 相似文献
10.
B P Griffith S R McCormick C K Fong J T Lavallee H L Lucia E Goff 《Journal of virology》1985,55(2):402-409
The development of cytomegalovirus (CMV) infection in the placenta was studied in Hartley guinea pigs inoculated at midgestation, and its role in determining the outcome of fetal CMV infection was assessed. A hematogenous spread of CMV from the mother to the placenta occurred early during the course of the infection. However, the virus remained present in placental tissues long after CMV had been cleared from maternal blood (i.e., 3 and 4 weeks postinoculation). At that time, the virus was able to replicate in placental tissues in the presence of specific maternal antibodies. Viral nucleocapsids were seen within nuclei of trophoblastic cells, and virions were present surrounding infected cells. In addition, typical CMV-induced histopathological lesions bearing CMV antigens were consistently localized at the transitional zone between the capillarized labyrinth and the noncapillarized interlobium. Whenever CMV infection of the fetus occurred, virus was isolated from the associated placenta. Among placental-fetal units with CMV-infected placentas, only 27% of the fetuses were found to be infected. In addition, there was a delay in the establishment of the infection in the fetus in relation to the placenta, although frequencies of virus isolation in placental and fetal tissues peaked at 3 weeks after CMV inoculation. These results suggest that during primary CMV infection of pregnant guinea pigs, the placenta not only serves as a reservoir for CMV but also acts to limit transmission of the virus to the fetus. 相似文献