[Retroaldol cleavage of the glyopeptide antibiotic ristomycin A during alkaline inactivation]. / O retroal'dol'nom rasshcheplenii antibiotika-glikopeptida ristomitsina A v khode shchelochnoi inaktivatsii.

The chemical and physicochemical characteristics of one of the two inactive components, i.e. the reduced product of alkaline inactivation (PAH-II) of ristomycin. A were studied. The components formed on the antibiotic incubation in mild alkaline media: 0.05 M NaOH, 37 degrees C, 1.5-2 hours. It was shown that the retroaldol cleavage of the C alpha-C beta bond of the phenol serine fragment of the trinuclear dideschlorvancomycinic acid G at the aglycone N-end was one of the causes of ristomycin A rapid inactivation under such conditions.

[Comparative biochemical study of 2 natural inactive variants of the actinomycin C producer Actinomyces sp. 26-115 with varying sensitivity to actinomycin]. / Sravnitel'noe biokhimicheskoe izuchenie dvukh estestvennykh neaktivnykh variantov produtsenta aktinomitsina C Actinomyces sp. 26-115 s razlichnoi chuvstvitel'nost'iu k aktinomitsinu.

Two natural variants of the actinomycin C-producing organism Actinomyces sp-26-115, i.e. H1 and H2 differ in their sensitivity to exogenic actinomycin, colony morphology, growth dynamics on the synthetic medium and stability to ultrasound and lysozyme. Both variants synthesize no actinomycin. Variant H1 is sensitive to exogenic actinomycin, while variant H2 is resistant to it. Variants H1 and H2 have some similarity in the composition of membrane proteins. Still, they differ in the protein molecular masses, which are equal to 600000--500000, 220000, 130000. The active variant A and nonactive variant H2 have the most similar compositions of membrane proteins. These variants are also close in their growth dynamics, colony morphology, sensitivity to ultrasound and lysozyme. The membranes of all the variants studied contain phosphatidyl ethanol amide as the main phospholipid component. Insignificant differences are observed only with respect to the minor components. The content of teichoic acids in the cell walls of variant H2 is very high, slightly changes during the developmental stage and insignificantly increases on addition of actinomycin to the medium. The cell wall of variant H1 contains less amounts of teichoic acids. During the developmental stage they are liberated from the wall at a higher rate than peptidoglycan. The sensitivity to actinomycin does not increase with an increase in the culture age. It is probable that teichoic acid of the cell wall is one of the factors providing resistance to actinomycin in variant H2. It may be considered as a barrier preventing transport of exogenic actinomycin into the cell.

[Membrane proteins of active and inactive variants of Actinomyces sp. 26-115, a producer of actinomycin C]. / Membrannye belki aktivnogo i neaktivnogo variantov Actinomyces sp. 26-115, produtsenta aktinomitsina C.

Some properties of the membrane proteins of Actinomyces sp. 26-115, i. e. its active variant and a variant not producing actinomycin C were studied comparatively. The membrane proteins of both variants of all ages tested represented a heterogenous fraction including about 30 protein components with a molecular mass of 17000 to 500000. There were differences in the protein component composition of the active and inactive variants. The membrane proteins of the active variant contained much more disulfide bonds than those of the inactive variant. It was shown in the model experiments on the protein binding of the phospholipid-lecithin membranes that the membrane proteins of the active variant bound higher amounts of lecithin during the whole developmental cycle than those of the inactive variant. It is suggested that the membrane proteins of the active variant had conformation differences as compared to those of the inactive variant.

[Characteristics of the active and inactive variants of Actinomyces sp. 26-115, a producer of actinomycin C]. / Nekotorye osobennosti aktivnogo i neaktivnogo variantov Actinomyces sp. 26-115, produtsenta aktinomitsina C.

Two natural variants, i.e. No. 1 and No. 2, not producing actinomycin were isolated from cultures of the actinomycin C-producing organism Actinomyces sp. 26-115. Variant No. 1 differed from the active variant by the growth dynamics and colony morphology. Variant No. 2 was close to the active variant by the growth dynamics. It was shown with electron microscopy that the cells of variant No. 1 differed from those of the active variant in the number and form of the mycelial septa, more even and compact structure of the cell walls and higher sensitivity to actinomycin. Still, they were more stable to the effect of lysozyme and ultrasound. The cell walls of the inactive variant No. 1 gradually lost teichoic acid during development, while the loss of peptidoglycan was observed only on transfer to the stationary phase. The cell walls of the active variant lost teichoic acid and peptidoglycan at the same time on transfer to the stationary phase. Peptidoglycans of both variants contained diaminopimelic acid (the configuration of which was not determined) and glycine (1:1) as differentiating amino acids. The two adjacent tetrapeptides were joined with one glycine radical. The peptidoglycan peptide chains of both variants contained muramic, glutamic and diaminopimelic acids and alanine (1:1:1:2). The peptidoglycans of the inactive variant No. 1 contained in addition valine and isoleucine. However, it is hardly probable that they are contained by the peptidoglycan peptide chains.

[New actinomycin from Actinomyces sp. No. 2]. / Novyi aktinomitsin iz Actinomyces sp. No. 2.

A new actinomycin was isolated from a mixture of actinomycins formed by Actinomyces sp. No. 2, an organism producing auranthin, an actinomycetous antibiotic. The peptide chains of the new actinomycin contain such amino acids as threonine, valine, proline and sarcosine in a ratio of 2 : 4 : 2 : 2. N-Methyl-valine characteristic of all actinomycins is replaced in position 5 of both pentapeptide chains of the new actinomycin by valine. The new actinomycin is actinomycin D undermethylated in position 5 by valine. When the growing culture of Actinomyces olivobrunneus producing actinomycin D was exposed to sulfadimesine, an inhibitor of biological methylation, production of actinomycin D0 (sarcosine replaced by glycine in one of the pentapeptide chains) markedly increased, which indicated impairment of the glycine residue methylation. Still, no impairment of the valine residue methylation in position 5 of the pentapeptide chains was observed an no actinomycin with N-methyl-valine replaced by valine was formed.

[Isolation of the membranes of Actinomyces sp. 26-115, a producer of actinomycin C]. / Poluchenie membran Actinomyces sp. 26-115, produtsenta.

A summation fraction of the membranes of Actinomyces sp. 26-115 was obtained as a result of lysis of its protoplasts in a hypotonic medium. The qualitative content of protein, lipids, phospholipids, nucleic acids, glucosamine and muramic acid was determined in the membranes at various stages of the organism development. Phosphatidylcholine is the main component of phospholipids in this organism. Intracellular actinomycin was found inside the protoplasts. Electrophoregrams of the microprotoplasts and membranes are presented. Actinomycin was also detected in the membranes. Still, it is not clear whether it is a component of the membrane or it is adsorbed on the membrane during the process of its isolation. The final conclusion on the relationship between the membrane and localization of actinomycin in the cell requires further investigation.

[Lysis of Micrococcus lysodeikticus protoplasts by gramicidin S derivatives]. / Lizis proizvodnymi gramitsidina S protoplastov Micrococcus lysodeikticus.

Gramicidin S derivatives with the substituted amino groups of ornithines (carbamoylgramicidin and diacetylgramicidin) possess nearly the same level of the lytic activity when acting on Micrococcus lysodeikticus protoplasts in a 1 M sucrose solution as the original antibiotic. The lytic activity of gramicidin S and these derivatives considerably increases in a solution of sucrose in phosphate buffer. The dependence of the lytic activity of gramicidin on its concentration is of a complex character: two "peaks" of activity and a region of "nonlyzing" concentrations. The lytic activity of gramicidin derivatives with substituted amino groups directly depends on the concentration. When gramicidin S acts upon the intact cells of M. lysodeikticus, it impair with the permeability of their membranes and causes a loss of compounds absorbing at 260 nm; the derivatives with the substituted amino groups change the permeability of the cellular membranes only to a slight extent.

[Aspects of the biosynthesis of actinomycin C]. / Nekotorye aspekty biosinteza aktinomitsina C.

The protoplasts of Actinomyces sp. 26--115 producing actinomycin C were obtained by the action of lysozyme on the mycelial paste of a 48-hour microbial culture. The protoplast capacity for synthesizing actinomycin was decreased as compared to that of the intact mycelium. The transport of L-isoleucine, a precursor of actinomycin C biosynthesis in the protoplasts also decreased but this could not be the only cause of the decrease in the actinomycin biosynthesis capacity. The biosynthesis of actinomycin C by the protoplasts of Actinomycin sp. 26--115 did not require galactose and was not inhibited by glucose and exogenic actinomycin.

[New amino acid from the antibiotic, ristomycin A]. / Novaia aminokislota iz antibiotika ristomitsina A.

A new amino acid E was isolated from a mixture of the products of the reductive hydrolysis of ristomycin A 57% HJ in the presence of red phosphorus. Its characterization was performed. The new amino acid was formed as a result of reductive dehydration of the respective beta-oxyamino acid present in the native antibiotic and being completely destroyed during general acid or alkaline hydrolysis.

[Separation of the biosynthesis products of a mutant strain of Actinomyces chrysomallus var. carotenoides and the identification of actinomycin antibiotics]. / Razdelenie produktov biosinteza mutantnogo shtamma Actinomyces chrysomallus var. carotenoides i identifikatsiia antibiotikov aktinomitsinov.

An orange antibiotically active substance isolated from the mycelium of a mutant strain of Actinomyces chrysomallus var. carotenoides was identified as a mixture of actinomycins according to its light absorption spectra, circular dichroism spectra, IR spectra and chromatographic comparison with the standard samples. A scheme for successive extraction of the biologically active substances from the mycelium resulting in isolation of a fraction enriched with antibiotic substances and a fraction enriched with pigments is presented. A method for separation and purification of 3 groups of biologically active substances from the mycelium enriched extract was developed.

[Effect of organic acids on the biosynthesis of macrotetralide antibiotics by an Actinomyces chrysomallus var. carotenoides strain]. / Vliianie organicheskikh kislot na biosintez makrotetralidnykh antibiotikov shtammom Actinomyces chrysomallus var. carotenoides.

The biosynthesis of macrotetrolides by Actinomyces chrysomalus var. carotenoides was stimulated by acetic, succinic, propionic, oxalic, malic, tartaric, citric, pyruvic, alpha-ketoglutaric and fumaric acids. Incorporation of 14C-acetate into the molecule of the antibiotic and the data on dependence of the stimulating effect upon the quantitative ratio and time of the organic acid addition were indicative of the role of acetic, succinic and propionic acids as precursors of macrotetrolides. The other organic acids increased the biosynthesis of macrotetolides when added to the culture within wide time ranges of the culture development and prolonged the period of the mycelium productive state.

[Heliomycin decrease in the pool of purine- and pyrimidine-containing compounds in bacterial cells]. / Snizhenie geliomitsinom pula purin- i pirimidinsoderzhashchikh soedinenii v bakterial'nykh kletkakh.

Heliomycin inhibited formation of the pool or purine and pyrimidine containing compounds in the cells of the growing cultures of Staphylococcus aureus and Escherichia coli both in the lag phase at the maximum rate of formation of the pool of compounds absorbing at 260 nm and in the exponential phase. A decrease in the concentration of purine and pyrimidine containing compounds in the acid-soluble fraction of the cells by the antibiotic was not caused by the disturbed permeability of the membranes. Apparently, heliomycin interfered with the regulation of RNA synthesis, either directly or through its action on the energy metabolism of the cells.

[Heliomycin suppression of RNA synthesis in a cell-free system]. / Podavlenie geliomitsinom sinteza RNK v beskletochnoi sisteme.

Heliomycin inhibited in vitro the RNA-polymerase reaction catalyzed by the preparation of DNA-dependent RNA-polymerase from E. coli. The blocking effect increased with a rise in the antibiotic concentration. The inhibitory effect of heliomycin decreased, when the amount of RNA-polymerase in the system increased. Yet, it did not depend on the content of DNA and the nature of the DNA preparation. Preincubation of RNA-polymerase with DNA resulting in formation of the enzyme-matrix complex did not prevent blocking RNA synthesis by heliomycin. Suppression of the RNA-polymerase reaction did not depend on the time of the antibiotic addition to the polymerizing system. Heliomycin had a significant activity not only with respect to the bacterial RNA-polymerase, but also in the system containing the enzyme isolated from the cells of Crithidia oncopelti.

[Quantitative amino acid makeup and the characteristics of the amino groups of ristomycin and the products of its partial acid hydrolysis]. / Kolichestvennyi aminokislotnyi sostav i kharakteristika aminogrupp ristomitsina i produktov ego chastichnogo kislotnogo gidroliza.

The quantitative amino acid composition of ristomycin A, a glycopeptide antibiotic, peptides I-IV (from partial acid hydrolysis of the antibiotic) and their dinitrophenylic derivatives was determined. It was shown that both ristomycin and free peptides I-IV contained one residue of ristomycinic acid and one residue of actinoidinic acid, diamino-dicarbonic amino acids of the glycylphenolic type. Peptides I-IV had close molecular weights, i.e. 1100-1200 and differed from each other in the gradually increasing numbers of NH2- and COON- groups, from one in peptide I to four in peptide IV. The quantitative amino acid analysis of the dinitrophenylic derivatives of ristomycin and peptides I-IV showed that the free NH2-group in peptide I belonged to ristomycinic acid, the same as in the antibiotic, while in peptides III-IV at least one of the free NH2-groups belonged to ristomycinic acid and the other belonged to actinoidinic acid.