Comparison of cytoplasmic informosome proteins with RNA-binding proteins and translation initiation factors from rabbit reticulocytes.

Using one-and two-dimensional electrophoresis, the free and polyribosomal informosome proteins and a preparation of total RNA-binding proteins from rabbit reticulocytes were compared. It was shown that the major proteins of free and polyribosomal informosomes are similar only to the minor components of RNA-binding proteins. On the other hand, the major RNA-binding proteins, two of which are elongation translation factors EF-1L and EF2, can be present in informosome preparations only as minor components. The major proteins of polyribosomal informosomes do not coincide in terms of electrophoretic mobility with initiation factors eIF-2, eIF-2A, eIF-3, eIF-4A and eIF-4B. The major proteins of free informosomes differ in their electrophoretic mobility from initiation factors eIF-2A, eIF-4A and eIF-4B as well as from the alpha- and beta-subunits of initiation factor eIF-2.     

5-Heteroatom-substituted pyrazoles as canine COX-2 inhibitors: Part 2. Structure-activity relationship studies of 5-alkylethers and 5-thioethers

Structure-activity relationship (SAR) studies of novel 2-[3-trifluoromethyl-5-alkyl(thio)ether pyrazo-1-yl]-5-methanesulfonyl pyridine derivatives for canine COX enzymes are described. The 4-cyano-5-alkyl ethers were found to have excellent potency and selectivity, whereas the 5-thioethers were potent but less selective than the ether analogs in a canine whole blood (CWB) COX-2 assay.     

A special repressor/activator system controls distribution of mRNA between translationally active and inactive mRNPs in rabbit reticulocytes

Translation of free mRNPs and polyribosomal mRNPs from rabbit reticulocytes was studied in a rabbit reticulocyte and wheat germ cell-free systems. It has been shown that translation efficiency of polyribosomal mRNPs and the mRNA isolated from the particles is nearly the same in both systems. At the same time, mRNP's translatability, which is high in the homologous cell-free system, is very low in the system from wheat germs. Translation efficiency of free mRNPs in the wheat germ system can be restored by addition of 0.5 M K CI-wash of rabbit reticulocyte ribosomes. The results testify to the existence of some special repressor repressor/activator system which controls the distribution of mRNA between free mRNPs and polyribosomes in rabbit reticulocytes.     

Biosynthesis of gramine in Phalaris arundinacea

The administration of L-tryptophan-[3-¹⁴C] to Phalaris arundinacea L. (Vantage strain) for 9 days resulted in the formation of radioactive gramine (8.2% absolute incorporation). A systematic degradation of the alkaloid indicated that essentially all its activity was located on the methylene group, indicating that its biosynthesis is the same as that occurring in Hordeum species and Lupinus hartwegii.