Synthesis of oligoribonucleotides by the N-phosphonate method using alkali-labile 2'-o-protective groups. II. Various aspects of using 2'-o-benzoyl and anisole protective groups

The N-acyl, 5'-O-trityl (MeOTr, (MeO)2Tr, Me3Tr), 2'-O-benzoyl (and anisole) nucleosides were prepared by selective aroylation of N,5'-protected nucleosides. By means of the reverse-phase microcolumn liquid chromatography it was shown that the rate of the aryl 2'----3'-isomerisation is lower in case of 2'-anisoylnucleosides and depends on structure of the 5'-O-protecting group. The prepared synthons were used for the manual H-phosphonate solid-phase synthesis of oligoribonucleotides (6-10-mers).     

Intrinsic fluorescence as a probe of structure-function relationships in Ca2+-transport ATPases

Applications of intrinsic fluorescence measurements in the study of Ca²⁺-transport ATPases are reviewed. Since the initial reports showing that the fluorescence emission was sensitive to Ca²⁺ binding, a substantial amount of work has focused on the use of both steady-state and time-resolved fluorescence spectroscopy to investigate structure-function relationships in sarcoplasmic reticulum and plasma membrane Ca²⁺-ATPases. These studies have revealed ligand-induced conformational changes, as well as provided information on protein-protein, protein-solvent and/or protein-lipid interactions in different functional states of these proteins. The main results of these studies, as well as possible future prospects are discussed.     

Anaphylactogenic, antigeni and avid properties of the antibotulin serum from the blood of various animal species]

It was shown that purified and concentrated by the "Diaferm" method antibotulin sera from horse and cattle blood failed to differ by anaphylactogenic properties; at the same time in sensitization of the organism to protein of one animal species the use of the sera of another species provided a lesser reactogenicity of the preparation. The antigenic activity of the purified and concentrated sera from the blood or horses and cows in testing on rabbits was identical, but in response to cow alpha-globulin the animals responsed by a more intensive production of precipitins. The activity of cow and horse antibotulin serum (determined by the rate and stability of their association with the corresponding toxin) proved to be identical.     

Genetic analysis of an osmotic sensitive

Summary The genetic analysis of VY1160 sorbitol dependent, osmotic sensitive yeast mutant led to the identification of three different nuclear recessive mutations. Two of them, designated sorb^- and ts1 are closely linked to one another. The mutation sorb^- determines the lysis, while the mutation tsl increases the ability for lysis of the sorbitol dependent cells. The third mutation ts2 segregates independently from the other two and confers the sensitivity of VY1160 mutant cells towards rifampicin.     

Book reviews

Ohne Zusammenfassung

---

Book reviews

     

Genetic studies of phosphoglucomutase-1 (PGM1) subtypes: population aspects]

Distribution of the subtypes and gene frequencies of phosphoglucomutase-1 among some populations of Buryats, Kirghizes of the Pamir and Russians of Moscow district was analysed. The frequencies of PGM1 genes vary in Buryats being PGM1+(1) 0.647-0.743, PGM1-(1)-0.100-0.132, PGM2+(1)-0.122-0.199 and PGM2-(1)-0.007-0.037. Following frequencies of PGM1 genes were established for Kirghizes: PGM1+(1) = 0.614, PGM1-(1) = 0.114, PGM2+(1) = 0.217 and PGM2-(1) = 0.054; in Russian populations the frequencies were: PGM1+(1) = 0.578, PGM1-(1) = 0.110, PGM2+(1) = 0.253 and PGM2-(1) = 0.059. Peculiarities of PGM1 polymorphism in the USSR and all over the world were analysed. Parallel biodemographic investigations in Buryat population demonstrated differences in intensities of selection, related to concrete PGM genotypes.     

Protection against acute paraquat toxicity by ambroxol

An expression vector for G-CSF, pASLB3-3, was constructed and introduced into Namalwa KJM-1 cells (Hosoi et al., 1988), and cells resistant to 100 nM of methotrexate (MTX) were obtained. Among them, the highest producer, clone SC57, was selected and the productivity of this clone was further characterized. The maximal production of G-CSF was at the most 1.8 g/ml/day using a 25 cm² tissue culture flask, even though the cell number was above 7×10⁵ cells/ml. The limiting factors at high density were analyzed as the deficiency of nutrients, such as glucose, cysteine and serine, and pH control. The depression of specific G-CSF productivity per cell under the batch culture conditions was overcome by using a perfusion culture system, Biofermenter^TM (Sato, 1983) with modifications of nutrients supplementation by a dialysis membrane and/or dissolved oxygen (DO) supplementation by microsilicone fibers. ITPSGF medium was modified to elevate concentrations of amino acids and glucose by 2.0- and 2.5-times, respectively. Under the control of pH at 7.4 and DO at 3 ppm, the specific G-CSF productivity was not depressed even at high cell density (above 1×10⁷ cells/ml), and the amount of G-CSF reached 41 g/ml. These results indicated the possibility of finding the optimum culture conditions for the production of recombinant proteins by Namalwa KJM-1 cells.Abbreviations ABTS 2,2-Azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid - BSA Bovine Serum Albumin - BSA-PBS Phosphate-buffered Saline without Ca²⁺ and Mg²⁺ containing Bovine Serum Albumin - dhfr Dihydrofolate Reductase - DO Dissolved Oxygen - G-CSF Granulocyte Colony-stimulating Factor - HEPES 4-(2-Hydroxyethyl)-1-piperazineethansulfonic Acid - IFN Interferon - MTX Methotrexate - PBS(-) Phosphate-buffered saline without Ca²⁺ and Mg²⁺ - Tween-PBS Phosphate-buffered saline without Ca²⁺ and Mg²⁺ containing 0.05% of Tween 20