Stepwise synthesis of oligonucleotides. XXXIV. Preparative synthesis of trinucleoside diphosphates and longer oligoribonucleotides using immobilized ribonucleases

Immobilized guanyl-specific ribonucleases from Aspergillus clavatus (C2), A. oryzae (T1), and Bacillus intermedius 7P (Bi) have been used for preparative synthesis of ten trinucleoside diphosphates, three tetra- and one pentanucleotide having the only guanylic acid residue at the 5'-end. The nucleotide sequence of the oligonucleotide synthesised determined the choice of the ribonuclease.     

Comparative study of the phospholipase activity of pathogenic and saprophytic Leptospira cultured on a serum-lecithin agar

The phospholipase activity of leptospires cultivated on serum-lecithin agar has been studied. Two zones of changes in the medium have been found to appear around the colonies of saprophytic Leptospira strains: transparent (5.25 +/- 2.09 mm wide) and turbid (6.90 +/- +/- 1.46 mm wide), which is linked with the production of phospholipases A and C. Only a single clear zone is formed around the colonies of pathogenic strains due to the production of phospholipase A. At the same time virulent Leptospira strains show greater phospholipase activity (the zones are 6.0 +/- 1.2 mm wide) than avirulent strains (the zones are 1.6 +/- +/- 0.04 mm wide).