[Specificity of intracellular ribonucleases Pc1 and Pc2 of the fungus Penicillium claviforme]. / Spetsifichnost' vnutrikletochnykh ribonukleaz Pc1 i Pc2 griba Penicillium claviforme.

The products of RNA and synthetic polynucleotides degradation by intracellular RNAses Pc1 and Pc2 of the fungus Penicillium claviforme were studied. It was shown that the enzymes possess the endonuclease activity and are not specific for the bases vicinal to the cleaved PDE bonds (EC 3.1.4.23). The increase of binding of the dinucleoside monophosphates by Pc1 and Pc2 dependent on the nucleoside at the 3'-end of the PDE bond is: A greater than C greater than G greater than U. This order is opposite for the rates of these substrates cleavage by the RNAses. A homologous specificity of the intracellular RNAse Pc1 and the extracellular RNAse II of Pen. claviforme has been revealed.

[The influence of the composition of the culture medium on the isoenzyme spectrum of Penicillium claviforme ribonucleases]. / Vliianie sostava sredy dlia kul'tivirovaniia na izofermentnyi spektr ribonukleaz Penicillum claviforme

The dynamics of the activity of extracellular and intracellular RNases was studied with Penicillium claviforme growing (1) on the modified Ogata medium and (2) on the medium whose composition was optimized for biosynthesis of intracellular RNases. RNA-depolymerazing enzymes were compared when produced on the media 1 and 2. The isoenzyme composition of RNases was the same on both media though the ratio between the components and the time of their appearance were different. Changes in the activities of RNase, PME, and protease were similar during cultivation of Pen. claviforme on the media 1 and 2.

[Production and properties of a beta-galactosidase preparation from Alternaria tenuis]. / Poluchenie i svoistva preparata beta-galaktozidazy iz Alternaria tenuis

Different methods of the preparation of fungal beta-galactosidase from the 72-hour culture of Alternaria tenuis were tested: lyophilization of the culture liquid, precipitation with ethanol, acetone, ammonium sulphate. Optimal results were obtained with precipitation by 1.5 acetone volume. Studies of the properties of fungal beta-galactosidase demonstrated that the preparation retained its activity during 22 month storage at 5 degrees C. The fungal preparation had pH optimum at a more acidic zone (4.2 versus 6.9), was active in a wider pH range 2.8-5.7 and 6.2-7.5), had a much higher temperature optimum (65 degrees and 30 degrees) and better thermostability as compared with the yeast preparation. Data on other properties of the preparation are presented.