Effects of air ions on the membrane Na, K-ATPase activity of L 1210 cells

The effect of exposure of L 1210 mouse leukemia cells to artificially generated air ions on the activity of membrane Na, K-ATPase in the cells was investigated. The exposure of cells to air ions of both signs gave identical results, i.e. diminution of transport activity of the enzyme, measured by radioactive 86Rb transport into the cell (ouabain-dependent). Passive ouabain-independent transport of Rb+ into the cells remained unchanged in the air ion-treated cells, as did the passive efflux of the radioisotope from preloaded cells. The possible explanation of the phenomena observed is discussed.     

Free,cytoskeletal-bound and membrane-bound polysomes isolated from MPC-11 and Krebs II ascites cells differ in their complement of poly(A) binding proteins

A three-step detergent/salt extraction procedure (Vedeleret al., Mol Cell Biochem 100: 183–193, 1991) was used to isolate free polysomes (FP), cytoskeletal-bound polysomes (CBP) and membrane-bound polysomes (MBP) from MPC-11 and Krebs II ascites cells. Polysomes were pelleted, washed with high salt buffer and re-pelleted. Proteins in the dialysed high-salt extracts were subjected to poly(A) Sepharose chromatography and poly(A) binding and non-binding proteins were separated by SDS-PAGE. In MPC-11 cells the FP fraction contains thirteen poly(A) binding proteins and four non-poly(A) binding proteins while the corresponding fraction in Krebs II ascites cells has four poly(A) binding proteins and six proteins which do not bind poly(A). The CBP fraction isolated from MPC-11 cells has a complement of ten poly(A) binding proteins, four which are non-poly(A) binding, and a protein of 105 kDa which has both poly(A) binding and non-poly(A) binding properties. In the CBP fraction prepared from Krebs II ascites cells a protein band at 32 kDa exhibits both poly(A) binding and non-poly(A) binding properties. In this fraction there are six poly(A) binding proteins and an additional eight which do not bind poly(A). Of the total number of proteins eight of these have a molecular weight below 40 kDa. The MBP fraction in MPC-11 cells contains three poly(A) binding proteins and eleven with non-poly(A) binding properties. In contrast this fraction in Krebs II ascites cells has a complement of thirteen poly(A) binding and ten non-poly(A) binding proteins. The results show differences in the poly(A) binding properties of the proteins in the three polysome fractions and that the complements of polysome-associated proteins are different in the two cell lines. This may be related to the differences in the growth characteristics of MPC-11 and Krebs II ascites cells.     

Assembly of an antibody and its derived antibody fragment inNicotiana andArabidopsis

The yield and assembly of an IgG1 antibody and its derived F_ab fragment were compared inNicotiana andArabidopsis. The results obtained showed a lot of interclonal variability. For 45% of the primary transgenic calluses, antigen-binding entities represented less than 0.1% of the total soluble protein (TSP). Only two of the 103 analysed transformants contained more than 1% of antigen-binding protein, with 1.26% being the highest yield. Analogous amounts of complete antibody and F_ab accumulated in primary callus tissue. Moreover, yields were in the same range for both species as far as primary callus tissue is concerned. However, the accumulation of the F_ab fragment in leaf tissue of regenerated plants differed significantly betweenNicotiana andArabidopsis. The F_ab fragment accumulated to only 0.044% of TSP inNicotiana leaves but up to 1.3% inArabidopsis leaves. Furthermore, both species showed differences in the assembly pattern of the complete antibody. WhereasArabidopsis contained primarily fully assembled antibodies of 150 kDa,Nicotiana showed an abundance of fragments in the 50 kDa range.     

Über die Innervation der Gaumendrüsen bei den Vögeln

Ohne Zusammenfassung     

Die De- und Regeneration des Peripheren motorischen Nervensystems auf einer morphologischfunktionellen Grundlage

Ohne Zusammenfassung