[Analysis of the quaternary structure of secreted repressible acid phosphatase from the yeast Saccharomyces cerevisiae]. / Analiz chetvertichnoi struktury sekretiruemoi repressibel'noi kisloi fosfatazy drozhzhei Saccharomyces cerevisiae.

The structural organization of extracellular repressible acid phosphatase from S. cerevisiae has been studied. The existence of multiple acid phosphatase forms with isoelectric points at pH 4.1-4.8 has been confirmed by isoelectrofocusing. The molecular masses of three acid phosphatase isoforms (56, 57-59, and 60 kDa) obtained after enzymatic deglycosylation correlate with the data obtained previously during the analysis of translation products in cell-free systems. Electron microscopic studies revealed that the acid phosphatase molecule has a square shape and is made up of four identical subunits with molecular masses of about 125 kDa.

[Ribosomes with unique breaks in 16S RNA: isolation and biological activity]. / Ribosomy s odinochnymi razryvami v 16S RNK: poluchenie i biologicheskaia aktivnost'.

A set of Escherichia coli 16S rRNA having unique breaks were prepared using the method of oligodeoxyribonucleotide-directed fragmentation with RNAse H. 16S RNA remained compact or dissociated to separate fragments, depending on the cleavage site location in the RNA structure. 16S rRNAs which have been split at different sites or their isolated fragments were used for a reconstitution of the 30S ribosomal subunits. These reconstituted 30S subunits carrying unique breaks at positions 301, 772, 1047 have the same sedimentation coefficients and electron microscopy images as the native subunit. They were active in the poly(U)-directed cell-free system of synthesis of polyphenylalanine.

[Purification, properties and quaternary structure of glutamine synthetase from Chlorella]. / Ochistka, svoistva i chetvertichnaia struktura glutaminsintetazy Khlorelly

A highly purified preparation of glutamine synthetase from chlorella grown on a medium containing nitrate as a sole source of nitrogen, was isolated and characterized by disc-electrophoresis and analytical ultracentrifugation. The N-terminal amino acid of glutamine synthetase is glycine. The molecular weight of glutamine synthetase is 32.000; its activity in the presence of Mg2+ was 150 mkmol o-phosphate per min per mg protein. The molecular weight of subunits of the enzyme, equal to 53.000 was determined by disc-electrophoresis in polyacrylamide gel in the presence of sodium dodecyl sulfate. Electron microscopy of negatively contrasted enzyme preparations revealed 6 subunits in the enzyme molecule, arranged in a point symmetry group 32.