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Inhibition of protein synthesis by spermine in growing cells of Staphylococcus aureus
Abstract:
Friedman, Mischa E. (Hebrew University, Jerusalem, Israel), and Uriel Bachrach. Inhibition of protein synthesis by spermine in growing cells of Staphylococcus aureus. J. Bacteriol. 92:49-55. 1966.-Staphylococcus aureus SFL 9725 incorporated valine-C(14) into cellular protein. This incorporation was inhibited by spermine when the pH of the culture was adjusted to 7.8, and the inhibition was antagonized partially by Mg(++). The incorporation of C(14)-labeled leucine, phenylalanine, lysine, arginine, and possibly glutamic acid was inhibited to a much greater extent than that of alanine, glycine, or threonine. The uptake of spermine-C(14) by S. aureus cells was rapid. More than 50% of the radioactivity resided in the soluble extract. The protein fraction of the soluble extract contained 99% of the recovered label, whereas the ribonucleic acid and deoxyribonucleic acid fractions contained little or no spermine-C(14).
Insights
Spermine inhibits protein synthesis in Staphylococcus aureus by affecting specific amino acid incorporation. Magnesium ions partially counteract this effect, influencing bacterial growth.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Bacterial protein synthesis is crucial for growth and survival.
- Polyamines like spermine can influence cellular processes.
- Staphylococcus aureus is a significant human pathogen.
Purpose of the Study:
- To investigate the effect of spermine on protein synthesis in Staphylococcus aureus.
- To determine the specificity of spermine's inhibitory action on amino acid incorporation.
- To explore the role of magnesium ions in spermine-mediated inhibition.
Main Methods:
- Utilizing Staphylococcus aureus SFL 9725.
- Measuring the incorporation of radiolabeled amino acids (e.g., valine-C14) into cellular protein.
- Adjusting culture pH to 7.8 and observing the effects of spermine and Mg(++) addition.
- Analyzing the subcellular distribution of radiolabeled spermine.
Main Results:
- Spermine significantly inhibited the incorporation of valine-C14 into protein at pH 7.8.
- Magnesium ions partially antagonized spermine's inhibitory effect.
- The inhibition was more pronounced for certain amino acids (leucine, phenylalanine, lysine, arginine, glutamic acid) compared to others (alanine, glycine, threonine).
- Spermine-C14 was rapidly taken up by cells, with most radioactivity found in the soluble protein fraction.
Conclusions:
- Spermine inhibits protein synthesis in Staphylococcus aureus, particularly affecting the incorporation of specific amino acids.
- Magnesium ions play a role in modulating spermine's inhibitory effects.
- Spermine primarily associates with the protein fraction within the soluble cellular components.