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Biomedical subjects

G Bellemare

Publications and source records attributed to G Bellemare.

At least 55 records · Page 3Linked to original sources
PubMed1979

Ribosomes of Physarum polycephalum. Subunits and protein composition.

Ribosomes from Physarum polycephalum were purified. Optimal conditions for preparation and stability of subunits were determined. KCl concentration above 200 mM induced protein dissociation from the subunits. It was observed that dissociated ribosomes were more stable in a low ionic strength buffer than in 200 mM KCl, where the 40 S was preferentially degraded by ribonucleases. Ribosomal proteins were analyzed by two-dimensional gel electrophoresis. The first dimension was carried out at pH 8.6 while the second was run at pH 4.6. The monosome contained sixty seven proteins, of which six were acidic. Two proteins were lost after subunit dissociation. Twenty six basic and two acidic proteins were observed in the 40 S subunit while the largest subunit gave thirty nine spots on the basic part of the gel and three additional spots on the acidic side. Five proteins were shared by 40 S and 60 S.

Electrophoresis, Polyacrylamide Gel↗
PubMed1979

Synthesis of chloroplast ribonucleic acid in Chlamydomonas reinhardtii toluene-treated cells.

Chlamydomonas reinhardtii cells treated with toluene at 0 degrees C and 25 degrees C incorporate ribonucleoside triphosphates (NTPs) into chloroplast RNA at 25 degrees C and also at 35 degrees C. The incorporation requires all four NTPs and Mg2+, and is completely inhibited by DNase, RNase, actinomycin D (40 microgram/ml) and rifampicin (350 microgram/ml). However, the incorporation is almost totally insensitive to both alpha-amanitin and streptolydigin at 200 microgram/ml.

Amanitins↗
PubMed1978

Nucleotide sequence of Halobacterium cutirubrum ribosomal 5 S ribonucleic acid. An altered secondary structure in halophilic organisms.

The nucleotide sequence of ribosomal 5 S RNA from a halophilic bacterium, Halobacterium cutirubrum, grown in 4 M sodium chloride is U-U-A-A-G-G-C-G-G-C-C-A-U-A-G-C-G-G-U-G-G-G-G-U-U-A-C-U-C-C-C-G-U-A-C-C-C-A-U-C-C-C-G-A-A-C-A-C-G-G-A-A-G-A-U-A-A-G-C-C-C-G-C-C-U-G-C-G-U-U-C-C-G-G-U-C-A-G-U-A-C-U-G-G-A-G-U-G-C-G-A-G-C-C-U-C-U-G-G-G-A-A-A-U-C-C-G-G-U-U-C-G-C-C-G-C-C-U-A-C-U. This nucleotide sequence is the longest prokaryotic 5 S rRNA to be reported and unlike other 5 S species does not contain a terminal mononucleoside diphosphate residue at its 5'-end. When compared to other 5 S rRNA's, the sequence homology is greatest (about 68%) with Bacillus subtilis; there is a lower but similar degree of homology (about 58%) with either Escherichia coli or human 5 S RNA. The comparisons further indicate that among 5 S RNA's, eleven of the nucleotide residues are unique to H. cutirubrum. Estimates of the secondary structure of the H. cutirubrum 5 S RNA molecule contain one additional stable hairpin loop which is not found in other 5 S rRNA species; this unusual structure is probably an adaptation to the high salt environment within H. cutirubrum cells.

Base Sequence↗
PubMed1975

Free and membrane-bound ribosomes. II. Two-dimensional gel electrophoresis of proteins from free and membrane-bound rabbit reticulocyte ribosomes.

Free and membrane-bound polysomes were isolated from rabbit reticulocytes. The membrane-bound polysomes were liberated form the membrane with deoxycholate. Monosomes were prepared from the two types of polysomes by incubation with puromycin. The ribosomal proteins were extracted and analyzed by two-dimensional gel electrophoresis. Two proteins of the large subunit, L11 and L17 present in the free monosomes were not found in the membrane-bound monosomes. On the other hand, four additional spots were found in the protein pattern of the membrane-bound monosomes.

Animals↗