β-Puromycin Selection of Modified Ribosomes for in Vitro Incorporation of β-Amino Acids

Biochemistry ◽  
2011 ◽  
Vol 51 (1) ◽  
pp. 401-415 ◽  
Author(s):  
Larisa M. Dedkova ◽  
Nour Eddine Fahmi ◽  
Rakesh Paul ◽  
Melissa del Rosario ◽  
Liqiang Zhang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Puromycin Selection ◽  
Selection Of

REMOVAL OF HUMAN ANTIBODIES TO FACTOR VIII :C FROM HEMOPHILIAC PLASMA USING NEW SYNTHETIC SORBENTS

1987 ◽  
Author(s):  
H Messaïkeh ◽  
N Belattar ◽  
D Gulino ◽  
J Jozefonvicz ◽  
Y Sultan
Keyword(s):  
Amino Acids ◽  
Factor Viii ◽  
Dimethyl Ester ◽  
Human Antibodies ◽  
Polystyrene Matrix ◽  
Crosslinked Polystyrene ◽  
Chemical Groups ◽  
The Relationship ◽  
Selection Of

Human antibodies that neutralize factor VIII procoagulant activity (Anti VIII:C) detected in polytransfused patients with hemophilia A cause serious difficulties for the affected patients as they inactivate any injected FVIII preparations.We hypothesized that FVIII:C might possess active sequences composed of amino acids able to bind Anti VIII:C antibodies. Consequently, completely synthetic resins with suitable chemical substituents mimicking these sequences might interact with Anti VIII:C antibodies. Based upon this hypothesis, crosslinked polystyrene was substituted by various amino acids or their derivatives in order to obtain completely synthetic adsorbents able to remove Anti VIII:C antibodies from hemophiliac plasmas. To establish the relationship between chemical composition of the resins and their affinity towards Anti VIII:C antibodies, the "in vitro" removal of these inhibitors from hemophiliac1s immunoglobulins G was tested by measuring simultaneous adsorptions of either IgG or Anti VIII:C antibodies. Specific and accurate methods veil adapted for studying the adsorption of these two kinds of proteins were used for evaluating either the IgG concentrations (rocket iirrnunoelectrophoresis) or the Anti VIII:C concentrations (immunoradicmetric method). To determine the most suitable chemical groups able to develop a specific adsorption, a first screening on amino acid substituents was undertaken and allowed the selection of glutamic acid and hydro -xyproline. In fact, among the twenty resins tested, the most interesting one is obtained by linking glutamic dimethyl ester derivative onto the polystyrene matrix. This resin possesses a pseudo-specificity towards Anti VIII :C antibodies as it is possible to remove 12 % of Anti VIII :C antibodies and only 3 % of IgG on 5 mg of this resin. Furthermore, the hydrophobic sites on the surface seems to be involved in the Anti VIII :C adsorption as demonstrated by comparing selectivity obtained with mono and diester derivatives either in aspartic or glutamic series.

Clone selection of in vitro horseradish hairy root cultures

Planta Medica ◽  
2015 ◽  
Vol 81 (16) ◽  
Author(s):  
R Bertóti ◽  
Á Alberti ◽  
A Böszörményi ◽  
R Könye ◽  
T Horváth ◽  
...  
Keyword(s):  
Hairy Root ◽  
Hairy Root Cultures ◽  
Root Cultures ◽  
Clone Selection ◽  
Selection Of

The Effects of Shock Vancomycin Concentrations on the Formation of Heteroresistance in Staphylococcus aureus

2020 ◽  
Vol 65 (9-10) ◽  
pp. 3-7
Author(s):  
V. V. Gostev ◽  
Yu. V. Sopova ◽  
O. S. Kalinogorskaya ◽  
M. E. Velizhanina ◽  
I. V. Lazareva ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
In Vitro Selection ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
High Concentration ◽  
Short Term ◽  
High Concentrations ◽  
Selection Of ◽  
Selection Of Resistance ◽  
Test Cultures

Glycopeptides are the basis of the treatment of infections caused by MRSA (Methicillin-Resistant Staphylococcus aureus). Previously, it was demonstrated that antibiotic tolerant phenotypes are formed during selection of resistance under the influence of high concentrations of antibiotics. The present study uses a similar in vitro selection model with vancomycin. Clinical isolates of MRSA belonging to genetic lines ST8 and ST239, as well as the MSSA (ATCC29213) strain, were included in the experiment. Test isolates were incubated for five hours in a medium with a high concentration of vancomycin (50 μg/ml). Test cultures were grown on the medium without antibiotic for 18 hours after each exposure. A total of ten exposure cycles were performed. Vancomycin was characterized by bacteriostatic action; the proportion of surviving cells after exposure was 70–100%. After selection, there was a slight increase in the MIC to vancomycin (MIC 2 μg/ml), teicoplanin (MIC 1.5–3 μg/ml) and daptomycin (MIC 0.25–2 μg/ml). According to the results of PAP analysis, all strains showed an increase in the area under curve depending on the concentration of vancomycin after selection, while a heteroresistant phenotype (with PAP/AUC 0.9) was detected in three isolates. All isolates showed walK mutations (T188S, D235N, E261V, V380I, and G223D). Exposure to short-term shock concentrations of vancomycin promotes the formation of heteroresistance in both MRSA and MSSA. Formation of VISA phenotypes is possible during therapy with vancomycin.

Wheat Germ Cell-Free Translation System as a Tool for In vitro Selection of Functional Proteins

2002 ◽  
Vol 5 (6) ◽  
pp. 473-480
Author(s):  
Bentham Science Publisher A.N. Alexandrov ◽  
Bentham Science Publisher V.Yu. Alakhov ◽  
Bentham Science Publisher A.I. Miroshnikov
Keyword(s):  
Germ Cell ◽  
Wheat Germ ◽  
In Vitro Selection ◽  
Translation System ◽  
Free Translation ◽  
Selection Of
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