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Biomedical subjects

M Rabinovitz

Publications and source records attributed to M Rabinovitz.

At least 127 records · Page 7Linked to original sources
PubMed1967

Membranes in polyribosome formation by rabbit reticulocytes.

When rabbit reticulocytes are incubated with n-butanol, an agent disruptive to the structure and function of cellular membranes, there is a rapid disaggregation of the polyribosomes. Reaggregation is promoted when the n-butanol is diluted below a critical concentration or when the cells are washed free of the alcohol and the incubation is continued. Neither disaggregation nor regeneration will occur in the absence of protein synthesis. These observations suggest that integrity of the reticulocyte membrane is necessary for the attachment of ribosomes to messenger RNA and for the formation of polyribosomes.

Adenosine Triphosphate↗
PubMed1967

Tryptophan deficiency in rabbit reticulocytes: polyribosomes during interrupted growth of hemoglobin chains.

Of several amino acids essential for optimum hemoglobin synthesis by the rabbit reticulocyte, only omission of tryptophan results in polyribosome disaggregation. This disaggregation is prevented by the omission of both tryptophan and an amino acid that is relatively more essential than tryptophan for hemoglobin synthesis. Since tryptophan is located only near the amino-terminal ends of both chains of rabbit globin, the results indicate that single ribosomes and those in polyribosomes are in a dynamic state in the intact cell.

Animals↗
PubMed1967

O-methylthreonine inhibition of growth and of threonine deaminase in Escherichia coli.

O-methylthreonine (OMT), an isosteric analogue of isoleucine, markedly inhibited growth of Escherichia coli 15. This inhibition was overcome most effectively by addition of isoleucine, valine, or leucine to the medium and less effectively by addition of threonine. The dipeptide, valylleucine, also relieved the OMT-induced inhibition but only after a lag period, suggesting that valine and leucine, liberated by dipeptidase action, compete with OMT for entry into the cell. OMT was activated and transferred to transfer ribonucleic acid (RNA) by isoleucyl-RNA synthetase in vitro. The rate of OMT incorporation into protein of intact cells was comparable to that of isoleucine. In contrast to isoleucine, very high concentrations of OMT were required to inhibit threonine deaminase, and the inhibition was strictly competitive with threonine. In addition, OMT inhibited a threonine deaminase preparation desensitized to isoleucine inhibition.

Adenosine Triphosphate↗