Separation of plant membranes by electromigration techniques

The review focuses on the multiple separating regimes that offers the free flow electrophoresis technique: free flow zone electrophoresis, isoelectric focusing, isotachophoresis, free flow step electrophoresis. Also, the feasibility to apply either interval or continuous flow electrophoresis is evaluated. The free flow zone electrophoresis regime is generally selected for the separation of cells, organelles and membranes while the other regimes find their largest fields of applications in the purification of proteins and peptides. The latter regimes present the highest resolution efficiency. Therefore, a large part of this review is devoted to the applicabilities of these different regimes to the purification of organelles and membrane vesicles at the preparative scale. Recent developments, both in instrumentation and procedures, are described. The major achievements in plant membrane fractionation obtained with free flow electrophoresis are outlined. The related procedures are both analytical and preparative: they separate tonoplast and plasma membrane simultaneously from the same homogenate, they discriminate for one type of membrane vesicles of opposite orientation, and process large quantities of membrane material by reason of the continuous flow mode. Recent advances using electromigration techniques that permit confirmation of the dynamic state of membranes, characterisation of complex membrane-dependent functions and discovery of new membrane-localised activities are presented.     

Profiling SARS-CoV-2 HLA-I peptidome reveals T cell epitopes from out-of-frame ORFs

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Cross-reactions between human and animal plasma proteins

Summary The rôle of several structural and functional factors and of concentration on the cross-reactions of 28 human plasma proteins with their homologues in animal blood was investigated. The Immunological Evolution Group (IEG) system was employed for this purpose as described earlier (Bauer, 1970 a). No interaction of structural factors was detected, while an influence of serum level of the different proteins could not be ruled out with certainty.At least in the case of the 4 immunoglobulins and the 3 complement factors, included in the IEG-system, protein function and evolution show some degree of correlation, indicating the influence of function on molecular evolution in the case of these plasma proteins.     

Optimization of speed and accuracy of decoding in translation

The speed and accuracy of protein synthesis are fundamental parameters for understanding the fitness of living cells, the quality control of translation, and the evolution of ribosomes. In this study, we analyse the speed and accuracy of the decoding step under conditions reproducing the high speed of translation in vivo. We show that error frequency is close to 10⁻³, consistent with the values measured in vivo. Selectivity is predominantly due to the differences in k_cat values for cognate and near-cognate reactions, whereas the intrinsic affinity differences are not used for tRNA discrimination. Thus, the ribosome seems to be optimized towards high speed of translation at the cost of fidelity. Competition with near- and non-cognate ternary complexes reduces the rate of GTP hydrolysis in the cognate ternary complex, but does not appreciably affect the rate-limiting tRNA accommodation step. The GTP hydrolysis step is crucial for the optimization of both the speed and accuracy, which explains the necessity for the trade-off between the two fundamental parameters of translation.     

Untersuchungen über gerbstoffführende Pflanzen

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Beitrag zur Phanerogamenflora der Bukowina und des angrenzenden Theiles von Siebenbürgen

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Pharmacological studies with beta-adrenoreceptor blocking agents I. Effect on the smooth muscle of the taenia coli of the guinea pig.

The action of new beta-blockers of VUFB series (VUFB 6502, VUFB 8102, VUFB 8227, and trimepranol) (Fig. 1) was analyzed in smooth msucle of guinea pig taenia coli by the double sucrose-gap method. All the studied beta-blockers increased the spontaneous spike activity without changes in membrane potential. The amino-analogues (VUFB 8101, VUFB 8102, VUFB 8227) as well as practolol were found to be 50 to 100 times less active than the oxy-derivatives (VUFB 6502 and Trimepranol) for the inhibition of spike activity, muscle relaxation and membrane hyperpolarization evoked by isoprenaline. None of the studied compounds had a pronounced alpha-blocking activity. The structure-activity relationship of the studied compounds was discussed.