scholarly journals Reassembly of the peptidyltransferase centre of larger subparticles of rabbit reticulocyte ribosomes from a core-particle and split-protein fraction

1976 ◽  
Vol 160 (3) ◽  
pp. 533-546 ◽  
Author(s):  
R A Cox ◽  
P Greenwell

We report the reconstruction, from a core-particle and split-protein fraction, of the larger subribosomal particle of rabbit reticulocytes. The reassembled particle was active in polyphenylalanine synthesis and in the puromycin reaction. The core-particles and split-protein fractions were obtained by treatment of the larger subparticle with salt solutions containing NH4+ and Mg2+ in the molar ratio 40:1 over the range 2.25-2.75 M-NH4Cl/56-69mM-MgCl2 at 0° C. This treatment led to the loss of about eight proteins (approx. 17% of the protein moiety), which were found wholly or largely in the split-protein fraction as shown by two-dimensional gel electrophoresis. The core particle retained 5S rRNA and had much decreased (no more than 10% of control) ability to function in the puromycin reaction or in poly (U)-directed polyphenylalanine synthesis. Activity was recovered when the recombined core-particle and split-protein fractions were dialysed overnight at 4° C against 0.3M-NH4Cl/15mM-MgCl2/1mM-dithiothreitol/15% (v/v) glycerol/20mM-Tris/HCl, pH 7.6, and then heated for 1 h at 37° C. The recovery was 40-80% of the original activity. Raising the concentration of MgCL2 to 300 mM in 2.5 M-NH4CL led to the removal of seven rather than eight proteins, and the core particle remained active in the puromycin reaction. We infer that the protein retained by raising the concentration of Mg2+ is an essential component of the peptidyltransferase centre of the ribosome.

1981 ◽  
Vol 194 (3) ◽  
pp. 931-939 ◽  
Author(s):  
R A Cox

The smaller subparticle of rabbit reticulocyte ribosomes was shown to yield core-particle and split-protein fractions on treatment with 2.5 M-NH4Cl/61 mM-MgCl2. The core-particle fraction was inactive in poly(U)-directed polyphenylalanine synthesis, but activity was restored after recombination with the split-protein fraction. Optimum ionic conditions for the reconstruction of active subparticles were found to be 0.75 M-NH4Cl/19 mM-MgCl2 at 0 degrees C. Improved extents of reconstruction were obtained when the core-particles were isolated by methods that avoided pelleting. Core-particles isolated from subparticles pretreated with either proteinases or ribonucleases had diminished capacity to become re-activated.


Virology ◽  
1995 ◽  
Vol 210 (1) ◽  
pp. 217-220 ◽  
Author(s):  
J.N. Burroughs ◽  
J.M. Grimes ◽  
P.P.C. Mertens ◽  
D.I. Stuart

2007 ◽  
Vol 1008 ◽  
Author(s):  
Clémentine Gautier ◽  
Rémi Courson ◽  
Pascal Jean Lopez ◽  
Jacques Livage ◽  
Thibaud Coradin

AbstractPore channels of poly-carbonate membranes were recently used as biomimetic models to study the effect of confinement on silicate condensation, leading to the formation of silica tubes exhibiting a core-shell structure. In this work, we pre-immobilized lysozyme on the membrane pores, inducing the modification of the tube shell formation process, and variation in core particle size. These data strengthen previous assumptions on the role of interfacial interactions on the growth of the tube shell and indicate that such interactions also influence the core particle formation. Such approach therefore seems suitable to mimic the formation of silica/protein multilayers as found in several biomineralizing organisms


2017 ◽  
Vol 31 (33) ◽  
pp. 1750307 ◽  
Author(s):  
Ersin Kantar

In this study, we examine by comparing the dynamic magnetic and hysteretic properties of Ising-type endohedral fullerene (EF) with various dopant magnetic particles confined within a spherical cage. The model of EF X@C[Formula: see text] with X = spin-1/2, spin-1 and spin-3/2 is proposed to study the effect of the nature of core particle on the magnetic properties. The results were obtained by mean-field theory as well as Glauber-type stochastic dynamics, and focused on the response of thermal and hysteretic behaviors of systems. The system exhibits second- and first-order phase transitions. In three different core cases, the system also exhibits type-II superconductivity behavior with a dynamic hysteresis curves of the core. All results display magnetic properties of the EF which strongly depend on the nature of core particle. Moreover, core particle and core/shell (C–S) interaction are proposed as the basic factors affecting the magnetic properties of EF system.


2005 ◽  
Vol 12 (4) ◽  
pp. 294-303 ◽  
Author(s):  
Marion Schmidt ◽  
Wilhelm Haas ◽  
Bernat Crosas ◽  
Patricia G Santamaria ◽  
Steven P Gygi ◽  
...  

1983 ◽  
Vol 3 (6) ◽  
pp. 974-981 ◽  
Author(s):  
E J Baker ◽  
A A Infante

The relative cytoplasmic accumulation of the individual histone mRNAs in sea urchins was determined by gel analysis of 3H-labeled cytoplasmic RNA isolated from embryos of the early cleavage through the mesenchyme blastula stages. A number of separate determinations showed that H1 mRNA accumulates at a molar ratio of 0.5 or less compared with each of the H2 or H3 core histone mRNAs through approximately the first 12 h of embryonic development. After this time, the accumulation of H1 mRNA increases relative to the core histone mRNAs, and approximately equimolar amounts of the histone mRNAs are produced by about the 14-h stage. The equimolar synthesis of H1 mRNA appears to be transient, returning to 0.5-molar levels several hours later. The increase in H1 mRNA accumulation, relative to the core histone RNAs, is coincident with the transition from expression of the early (alpha) sea urchin histone gene set to the late histone genes. Since all five of the early histone genes occur in a 1:1 ratio within repeating units, the data suggest that the genes within a single repeat, or their immediate products, are individually regulated. Gel analysis of the proteins synthesized in vivo by embryos demonstrates that the pattern of synthesis of the histone proteins reflects the changing ratios of the histone mRNAs.


The Analyst ◽  
2019 ◽  
Vol 144 (20) ◽  
pp. 5928-5933 ◽  
Author(s):  
Eduardo Paredes ◽  
Véronique Malard ◽  
Claude Vidaud ◽  
Emilie Avazeri ◽  
Richard Ortega ◽  
...  

Accurate isotope ratio determination was downscaled to the level of metal-containing protein fractions obtained from cell line lysates.


MRS Advances ◽  
2020 ◽  
Vol 5 (40-41) ◽  
pp. 2121-2127
Author(s):  
Ssu-Hao Huang ◽  
Pei-Hua Chen ◽  
Yan-Ping Chen ◽  
Muoi Tang

ABSTRACTThe polymerization of 3,4-ethylenedioxythiophene (EDOT) onto nanosilica (SiO2) was synthesized in this study by using supercritical carbon dioxide (SCCO2). With the addition of dopants of p-toluenesulfonic acid (p-TSA) or decylbenzene sulfonic acid (DBSA), the PEDOT/SiO2 composite became conductive. The product was characterized by FTIR spectroscopy and the core-shell structure was confirmed through the TEM images. The electrical properties were analyzed by UV-vis absorbance and four-point probe measurement. DBSA is shown as the better dopants with the molar ratio (DBSA/EDOT) of 0.2 at the reaction time of 48 hours. The maximum coating percentage is 63 wt% under the optimal operation conditions at 40oC and 280 bar. The conductivity is tuned up to 6.6×10-2 S/cm after the coating process.


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