Nucleotide composition of nucleic acids of fungi. II. Deoxyribonucleic acids

Storck, Roger (The University of Texas, Austin). Nucleotide composition of nucleic acids from fungi. II. Deoxyribonucleic acids. J. Bacteriol. 91:227-230. 1966.-The nucleotide composition of the deoxyribonucleic acids (DNA) present in extracts of 30 species of fungi was determined. The results were analyzed, together with those in the literature. It was found that the content, in moles per cent of guanine plus cytosine (GC content), varied from 38 to 63% in a distribution composed of 9 species of zygomycetes, 14 of ascomycetes, and 9 each of deuteromycetes and basidiomycetes. The GC content ranges were: 38 to 48% for the zygomycetes, 38 to 54% for the ascomycetes, 47 to 62% for the deuteromycetes, and 44 to 63% for the basidiomycetes. The GC content ranged from 38 to 40% for four Mucor species. The base composition of fungal DNA appears, therefore, to have a taxonomic and phylogenetic significance.     

Nucleotide composition of nucleic acids of fungi. I. Ribonucleic acids

Storck, Roger (The University of Texas, Austin). Nucleotide composition of nucleic acids from fungi. I. Ribonucleic acids. J. Bacteriol. 90:1260-1264. 1965.-The nucleotide composition of the ribonucleic acids (RNA) present in extracts of 26 species of fungi was determined. The results were analyzed, together with those in the literature. It was found that the content in moles per cent of guanine plus cytosine (GC content) varied from 44.1 to 60.5 in a distribution composed of 8 species of zygomycetes, 10 of ascomycetes, 11 of deuteromycetes, and 8 of basidiomycetes. The GC-content range and average were, respectively, 44.1 to 49.3 and 46.4 for the zygomycetes, 47.4 to 54.4 and 50.2 for the ascomycetes, 48.2 to 54.5 and 51.6 for the deuteromycetes, and 50.4 to 60.5 and 52.4 for the basidiomycetes. The GC content averaged 45.6 and ranged from 44.1 to 46.3 for four Mucor species. In addition, GC contents significantly lower than 50 were also encountered in some species of Hemiascomycetidae, suggesting that AT type RNA is not uncommon in fungi. It was proposed that the base composition of fungal RNA might have a taxonomic and phylogenetic significance.     

Interaction of nucleic acids. VI. Interaction of purine with nucleic acids

The interaction of purine with DNA, tRNA, poly A, poly C, and poly A. poly U complex was investigated. In the presence of purine, the nucleic acids in coil form (such as denatured DNA, poly A and poly C in neutral solutions, or tRNA) have lower optical rotations. In addition, hydrodynamic studies indicate that in purine solutions the denatured DNA has a higher viscosity and a decreased sedimentation coefficient. These findings indicate that through interaction with purine, the bases along the poly-nucleotide chain are unstacked and are separated farther from each other, resulting in increased assymmetry (and possibly volume) of the whole polymer. Thus, the de-naturation effect of purine reported previously can be explained by this preferential interaction of purine with the bases of nucleic acids in coil form through a hydrophobic-costacking mechanism. Results from studies on optical rotation and helix-coil transition show that the interaction of purine is greater with poly A than with poly C. The influence of temperature, Mg⁺⁺ concentration, ionic strength, and purine concentration on the effect of purine on nucleic acid conformation has also been investigated. In all these situations the unraveling of nucleic acid conformation occurs at much lower temperatures (20–40°C lower) in the presence of purine (0.2–0.6M).     

Microbial desulfonation of substituted naphthalenesulfonic acids and benzenesulfonic acids.

Sulfur-limited batch enrichment cultures containing one of nine multisubstituted naphthalenesulfonates and an inoculum from sewage yielded several taxa of bacteria which could quantitatively utilize 19 sulfonated aromatic compounds as the sole sulfur source for growth. Growth yields were about 4 kg of protein per mol of sulfur. Specific degradation rates were about 4 to 14 mu kat/kg of protein. A Pseudomonas sp., an Arthrobacter sp., and an unidentified bacterium were examined. Each desulfonated at least 16 aromatic compounds, none of which served as a carbon source. Pseudomonas sp. strain S-313 converted 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 5-amino-1-naphthalenesulfonic acid, benzenesulfonic acid, and 3-aminobenzenesulfonic acid to 1-naphthol, 2-naphthol, 5-amino-1-naphthol, phenol, and 3-aminophenol, respectively. Experiments with 18O2 showed that the hydroxyl group was derived from molecular oxygen.     

Synthesis of teichoic acids. VII. Synthesis of teichoic acids during spore germination

The synthesis of teichoic acids has been examined during germination in Bacillus licheniformis ATCC 9945 and in B. subtilis W-23. Teichoic acids are absent from the spores of both organisms. B. licheniformis spores lack the enzymes responsible for teichoic acid synthesis. The appearance of these enzymes during germination is correlated with the appearance of teichoic acids in the cell. The appearance of teichoic acid-synthesizing enzymes and of teichoic acids in the cell are inhibited by the addition of chloramphenicol to the germination medium. In B. subtilis W-23 the situation is similar for the synthesis of polyribitolphosphate. The synthesis of glucosyl polyribitolphosphate is only partially inhibited by chloramphenicol, puromycin, and penicillin, and uridine diphosphate-d-glucose polyribitol-phosphate glucosyl transferase can be demonstrated in spores. The possible implications of some of these observations are discussed.     

Chemical properties of bile acids. IV. Acidity constants of glycine-conjugated bile acids

The dissociation constants for the carboxyl group of a series of glycine (N-acyl)-conjugated and unconjugated bile acids were determined by potentiometric titration using dimethylsulfoxide-water and methanol-water mixtures of varying proportions. The pKa values in water were calculated by extrapolating the experimental values determined in different mole fractions of the organic solvent mixtures. The following values were obtained: 3.9 +/- 0.1 for glycine-conjugated bile acids and 5.0 +/- 0.1 for unconjugated bile acids, as general pKa values for the two classes of bile acids, respectively. The amidation of bile acids with glycine lowers the pKa value because of the proximity of the amide bond to the terminal carboxyl group. Bile acid dissociation constants are independent of the substituents in the steroid nucleus, since inductive effects of the hydroxyl groups on the steroid nucleus are too distant from the acidic group at the end of the side chain to influence its ionization.     

Transformation of some hydroxy amino acids to other amino acids.

It has been observed that beta-hydroxy-alpha-amino acids are transformed into other amino acids, when heated in dilute solutions with phosphorous acid, phosphoric acid or their ammonium salts. It has been shown that as in the case of previously reported glycine-aldehyde reactions, glycine also reacts with acetone to give beta-hydroxyvaline under prebiologically feasible conditions. It is suggested, therefore, that the formation of beta-hydroxy-alpha-amino acids and their transformation to other amino acids may have been a pathway for the synthesis of amino acids under primitive earth conditions.     

Mycolic acids. A reinvestigation.

Mycolic acids derived from the cell walls of Mycobacterium bovis BCG, Mycobacterium bovis Bovinus I, Mycobacterium smegmatis, and Mycobacterium tuberculosis H37Rv have been fractionated as their p-bromophenacyl esters by a two-step high performance liquid chromatographic procedure: 1) adsorption chromatography on 10-micrometer particle size silica gel, and 2) reverse phase partition chromatography on a 10-micrometer particle size support containing a C18 bonded phase. This procedure has resulted in the isolation of approximately 24 mycolic acids from each bacterium (very likely homologs of various mycolate types) instead of the two to four that have previously been described. The implication of these results on the previously determined structures of these fatty acids is discussed.     

Bile acids. XLVII. 12alpha-Hydroxylation of precursors of allo bile acids by rabbit liver microsomes.

Rabbit liver microsomal preparations fortified with 0.1 mM NADPH effectively promote hydroxylation of [3beta-3H]- or [24-14C]allochenodeoxycholic acid or [5alpha,6alpha-3H2]5alpha-cholestane-3alpha,7alpha-diol to their respective 12alpha-hydroxyl derivatives in yields of about 25 or 65% in 60 min. Minor amounts of other products are formed from the diol. The requirements for activity of rabbit liver microsomal 12alpha-hydroxylase resemble those of rat liver microsomes. Of a number of enzyme inhibitors studied only p-chloromercuribenzoate demonstrated a marked ability to inhibit the reaction with either tritiated substrate. There was no difference in the quantity of product produced from the tritiated acid or the 14C-labeled acid. No clear sex difference was found in activity of the enzyme, nor was an appreciable difference noted in activity of the enzyme between mature and immature animals.     

Aerobic catabolism of bile acids.

Seventy-eight stable cultures obtained by enrichment on media containing ox bile or a single bile acid were able to utilize one or more bile acids, as well as components of ox bile, as primary carbon sources for growth. All isolates were obligate aerobes, and most (70) were typical (48) or atypical (22) Pseudomonas strains, the remainder (8) being gram-positive actinomycetes. Of six Pseudomonas isolates selected for further study, five produced predominantly acidic catabolites after growth on glycocholic acid, but the sixth, Pseudomonas sp. ATCC 31752, accumulated as the principal product a neutral steroid catabolite. Optimum growth of Pseudomonas sp. ATCC 31752 on ox bile occurred at pH 7 to 8 and from 25 to 30 degrees C. No additional nutrients were required to sustain good growth, but growth was stimulated by the addition of ammonium sulfate and yeast extract. Good growth was obtained with a bile solids content of 40 g/liter in shaken flasks. A near-theoretical yield of neutral steroid catabolites, comprising a major (greater than 50%) and three minor products, was obtained from fermentor growth of ATCC 31752 in 6.7 g of ox bile solids per liter. The possible commercial exploitation of these findings to produce steroid drug intermediates for the pharmaceutical industry is discussed.     

Fluorimetric assay of sialic acids.

A fluorimetric assay has been developed for sialic acids in which sialic acids react with pyridoxamine to give fluorescent compounds in the presence of zinc ion and pyridine. This assay method is specific for unbound sialic acids and is a simple and sensitive procedure compared with the thiobarbituric acid assay of sialic acids.     

Stereospecific synthesis of trans-arachidonic acids.

An effective synthesis is described for the preparation of all four mono trans isomers of arachidonic acid via deoxidation of epoxide precursors with lithium diphenylphosphide and quaternization with methyl iodide.