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O Ciferri

Publications and source records attributed to O Ciferri.

34 records · Page 2Linked to original sources
PubMed1970

Incorporation of 5-methyl- and 5-hydroxy-tryptophan into the protein of Bacillus subtilis.

Addition of the tryptophan analogues 5-methyl-tryptophan, 5-hydroxy-tryptophan, and 7-aza-tryptophan, during tryptophan starvation of a tryptophan auxotroph of Bacillus subtilis, stimulated amino acid incorporation. Two of the analogues tested, 5-methyl-tryptophan and 5-hydroxy-tryptophan, competed with each other, but their addition did not prevent tryptophan incorporation into acid-insoluble material. The incorporation of tryptophan and 5-hydroxy-tryptophan was stimulated when a mixture of phenylalanine and tyrosine was present in the medium. The two analogues 5-methyl-tryptophan and 5-hydroxy-tryptophan were recovered in protein hydrolysates of analogue-grown cultures, and there is evidence suggesting that the analogues are not chain terminators. Neither analogue prevented the polysome degradation that occurs during tryptophan starvation.

Amino Acids↗
PubMed1970

Tryptophanless death in Bacillus subtilis.

A decline in colony-forming ability is observed in actively growing cultures of a tryptophan arginine auxotroph of Bacillus subtilis after removal of tryptophan (tryptophanless death). This phenomenon can be prevented by simultaneous starvation of the other required amino acid or by chloramphenicol administered in bacteriostatic concentration but not by actinomycin. Addition of tryptophan analogues not only prevents the death but also allows recovery of the cells that have lost the ability to form colonies on solid media. The term tryptophanless death is therefore inappropriate. Chloramphenicol but not actinomycin inhibits the recovery brought about by tryptophan analogues.

Amino Acids↗
PubMed1970

Uptake of synthetic polynucleotides by competent cells of Bacillus subtilis.

A survey was made of the capacity of competent cells of Bacillus subtilis to take up synthetic polynucleotides. Polydeoxyribonucleotides but not polyribonucleotides are taken up by the cells. Both types of polynucleotide failed to compete with transforming deoxyribonucleic acid in the transformation assay whereas both stimulated amino acid incorporation. The latter phenomenon appears to be nonspecific as there is no correlation between the codon composition of the polynucleotides employed and the amino acids whose incorporation was stimulated.

Amino Acids↗
PubMed1965

Origin of the sarcosine molecules of actinomycins.

1. Streptomyces V-187 produces on minimal medium a mixture composed mainly of actinomycin C(1) (actinomycin D) and actinomycin A(1) (actinomycin I). If sarcosine is added to the medium, the micro-organism produces, in addition to actinomycins C(1) and A(1), actinomycin F(8) (actinomycin II) and actinomycin F(9) (actinomycin (III), characterized by the substitution by sarcosine of one or both the proline molecules present in actinomycin C(1). 2. Exogenous sarcosine seems to be incorporated as such by Streptomyces V-187 only in the sarcosine molecule(s) that replace proline in the actinomycins of the F group, whereas, for the synthesis of the other sarcosine molecules, the amino acid is first demethylated to glycine. 3. The incorporation of sarcosine and glycine into actinomycin by Streptomyces antibioticus appears to follow a similar pattern, except that a portion of the methyl group produced in the degradation of sarcosine is utilized as a source of the methyl groups of the antibiotic. This explains the previously reported lack of cross-dilution between glycine and sarcosine observed in the incorporation of these amino acids into actinomycin.

Chromatography, Thin Layer↗