THE BIOSYNTHESIS OF ALKALINE PHOSPHATASE WITH A PARTICULATE FRACTION OF ESCHERICHIA COLI
| Autor: | C. Roche, A. Yapo, Manson La, J. Pelmont, B. Nisman |
|---|---|
| Rok vydání: | 1965 |
| Předmět: |
DNA
Bacterial General Mathematics Biology Phosphates chemistry.chemical_compound Biosynthesis Escherichia coli Nucleotide RNA Messenger Enzyme Inhibitors Molecular Biology Phosphorolysis chemistry.chemical_classification Pharmacology Manganese Nucleotides Applied Mathematics Protoplasts Research RNA DNA Articles Phosphate Alkaline Phosphatase beta-Galactosidase Molecular biology Amino acid Kinetics RNA Bacterial Enzyme Metabolism Biochemistry chemistry Mutation Alkaline phosphatase Enzyme Repression |
| Zdroj: | The Biochemical journal. 95 |
| ISSN: | 0264-6021 |
| Popis: | 1. By digitonin lysis of penicillin spheroplasts of Escherichia coli a particulate fraction P(1) was previously obtained that supported the sustained synthesis of alkaline phosphatase when supplied with amino acids, nucleotide triphosphates and other cofactors. This P(1) fraction, when subjected to mild ultrasonic treatment in the presence of sucrose and Mg(2+), yielded the P(1)(S) fraction, consisting of integrated particulate subcellular particles containing DNA and RNA. 2. The P(1)(S) fraction from E. coli K10 wild type (R(+) (1)R(+) (2)P(+)) grown under repressed conditions supported the immediate synthesis of alkaline phosphatase in vitro. The synthesis occurred in phases. The first was followed by a lag, and then there was a linear rapid phase that continued for at least 3hr. Actinomycin D inhibited the appearance of the second phase. It was concluded that the particles are programmed to synthesize enzyme even when prepared from repressed cells, and therefore that synthesis of the specific messenger RNA for alkaline phosphatase in vivo was not inhibited when the bacteria were grown in an excess of inorganic phosphate. 3. Phosphate inhibited synthesis of enzyme to the same extent with the P(1)(S) fractions of two constitutive strains as with the P(1)(S) fraction of the wild-type strain. 4. Inorganic phosphate inhibited amino acid incorporation with the P(1)(S) fraction and also inhibited enzyme synthesis in vitro. The effect on amino acid incorporation could be partially overcome by adding Mn(2+) to the incubation mixtures. However, Mn(2+) inhibited the synthesis of alkaline phosphatase. Also, inhibition of the incorporation of [(32)P]CTP into RNA was overcome by Mn(2+). The effect of phosphate on amino acid uptake was most probably due to a phosphorolysis of RNA by polynucleotide phosphorylase, also present in the P(1)(S) fraction. This phosphorolysis may be responsible for the instability of messenger RNA in vitro and in vivo. 5. Phosphate also specifically inhibited the formation of alkaline phosphatase, since it did not affect markedly the induced formation of beta-galactosidase by the same P(1)(S) fraction. The specific effect is attributed to the prevention of formation of the enzymically active dimer from precursors, a Zn(2+)-dependent reaction. It is suggested that the repression of the synthesis of alkaline phosphatase in vivo in the wild-type strain was the sum of these two effects. |
| Databáze: | OpenAIRE |
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