[Superoxide dismutase and catalase activities in carotenoid-synthesizing fungi Blakeslea trispora and Neurospora crassa under the oxidative stress]. / Aktivnost' superoksiddismutazy i katalazy u karotinoidsinteziruiushchikh gribov Blakeslea trispora i Neurospora crassa v usloviiakh okislitel'nogo stressa.

The addition of menadione into the medium during cultivation of Neurospora crassa in the dark activated its constitutive superoxide dismutase. Exposure to light not only activated superoxide dismutase and catalase, but also increased the content of neurosporaxanthin. Superoxide dismutase activity in the mixed (+/-) mycelium of Blakeslea trispora synthesizing beta-carotene in the dark was much lower than that in Neurospora crassa. The superoxide dismutase activity further decreased in oxidative stress. The catalase activity decreased with an increase in the content of beta-carotene. Our results indicate that neurosporaxanthin possesses photoprotective properties in Neurospora crassa. In Blakeslea trispora (+/-) fungi, this compound acts as a major antioxidant during inactivation of enzymes that detoxify reactive oxygen species.

[Biosynthesis and use of coproporphyrins and uroporphyrins and their metal complexes in immune analysis and diagnostic methods]. / Biosintez i primenenie koproporfirinov i uroporfirinov i ikh metallokompleksov v immnoanalize i diagnostike.

Methods of synthesis of coproporphyrin and uroporphyrin by using bacteria of the genus Arthrobacter are proposed. Metal complexes of coproporphyrin and uroporphyrin with Pt, Pd, and Zn were synthesized. Their structures were identified by spectrophotometry, IR spectrometry, 1H-NMR, mass spectrometry, and HPLC. Data showing the possibility to use coproporphyrin III-metal complexes as luminophores for fluorescence detection of tumors. The current and prospective uses of metal complexes of water-soluble natural porphyrins in advanced immunofluorescence assays are discussed.

[Features of the elemental composition of medicinal plants, synthesizing phenolic compounds]. / Osobennosti élementnogo sostava lekarstvennykh rastenii, sinteziruiushchikh fenol'nye soedineniia.

A total of 52 species of medicinal plants capable of synthesizing phenolic compounds were subjected to mass-scale screening for 24 chemical elements. The screening was performed by atomic absorption spectrometry in combination with spectrophotometric detection. The plant species tested were found to accumulate groups of two to ten chemical elements (Fe, Cr, Cu, Co, Mn, etc.), which are known cofactors and activators of many enzymes of phenol metabolism. Some of the plant species tested are overconcentrators of Cr, Co, Mn, I, and other chemical elements. The possibility of the use of these plants in the treatment and prophylaxis of disorders of the microelement metabolism is discussed.

[Tetrapyrroles: diversity, biosynthesis, biotechnology]. / Tetrapirroly: raznoobrazie, biosintez, biotekhnologiia.

Various aspects of metabolism and biotechnology of tetrapyrroles are reviewed. Structures and properties of newly discovered tetrapyrrole pigments, biosynthesis of most important functional tetrapyrroles (hemes, chlorophylls, corrinoids, siroheme, and methanogenesis factor F430), and biotechnological methods of production of porphyrins and corrinoids are discussed. 5-Aminolevulinic acid is shown to be a promising anticancer preparation.

[Conversion of beta-carotene and some beta-apocarotinoids under the effect of substances from the intestinal mucosa]. / Issledovanie prevrashcheniia beta-karotina i nekotorykh beta-apokarotinolov pod deistviem preparatov mukoidal'nogo sloia kishechnika.

Products of cleavage of beta-carotene and certain apocarotenoids (beta-apo-4', 8', 10', and 12'-carotenols and citranaxanthol) were studied, and the dynamics of their generation in the presence of an enzyme preparation isolated from rabbit intestinal mucosa was determined. The data suggest that metabolism of beta-apocarotenols involves the production of retinal and beta-apo-14'-carotenal mediated by enzymes different from beta-carotene-15,15'-dioxygenase, which converts beta-carotene to retinal. A scheme of metabolic conversion of beta-carotene is discussed.

[Radiation-protective effect of S-methylmethionine (vitamin U)]. / Protivoluchevoe deistvie S-metilmetionina (vitamina U).

S-Methylmethionine had moderate radioprotective activity, the efficiency of radioprotection was 15-30%, the value of dose decrease coefficient-1.2. Biological effect of S-methylmethionine was probably provided by its ability to decrease the level of lipid peroxidation and inhibit monoamine oxidase activity.

[Monoamine oxidase activity in rat liver in vitamin B12 deficiency]. / Monoaminooksidaznaia aktivnost' v pecheni krys pri nedostatochnosti vitamina B12.

Changes in the activity of monoamine oxidase (MAO-B) in liver homogenates and mitochondria from normal and vitamin B12-deficient rats have been studied in various functional states of the mitochondria. Preincubation of liver preparation at 32 degrees C increased the MAO affinity for benzylamine in samples of normal (but not vitamin B12-deficient rats). Succinate added to the incubation medium decreased Km and increased Vmax in both normal and vitamin B12-deficient animals. A correlation was found between the decline of MAO-B activity under vitamin B12 deficiency, deceleration of succinate oxidation and reduction of the transmembrane potential.

[Change in tryptamine metabolism in vitamin B12 deficiency]. / Izmenenie obmena triptamina pri dedostatochnosti vitamina B12.

The metabolism of tryptamine was studied in rats in health and in vitamin B12 deficiency. Excretion of cobalamin with urine before and after loading with tryptamine was studied. Daily excretion of tryptamine with urine in vitamin B12-deficient animals was normal or slightly increased. At the same time, the increase in tryptamine excretion with urine in response to tryptophan administration was 2-fold lower in vitamin B12-deficient rats as compared with controls. These data may be interpreted to occur due to a decrease in the rate of tryptamine metabolism in vitamin B12 deficiency in rats. Impairments in metabolism of biogenic amines appear to be involved in the development of neuro-mental diseases accompanied by vitamin B12 deficiency.

[The character of the interaction of beta-carotene-15,15'-dioxygenase from rabbit small intestine with lycopene, 15,15'-dehydro-beta-carotene, lutein, and astaxanthine]. / O kharaktere vzaimodeistviia beta-karotin-15,15'-dioksigenazy iz tonkogo kishechnika krolika s likopinom, 15,15'-degidro-beta-karotinom, liuteinom i astaksantinom.

Interaction of rabbit small intestine mucosa beta-carotene 15,15'-dioxygenase with lycopene, 15,15'-dehydro-beta-carotene, lutein and astaxanthine is unaccompanied by the formation of products of enzymatic cleavage of the central double bond of these carotenoid molecules. Apo-carotenoids of lutein and lycopene are formed by nonenzymatic oxidation. Lycopene and 15,15'-dehydro-beta-carotene competitively inhibit the enzymatic oxidation of beta-carotene. Inhibition of the enzyme conversion by lutein and astaxanthin is less strong, being of a competitive-noncompetitive type. Enzymatic formation of retinal from beta-carotene depends on the accessibility of substrate molecules.

[Metabolites of the propionate pathway as regulators of fatty and dicarboxylic acid oxidation in liver mitochondria]. / Metabolity propionatnogo puti kak reguliatory okisleniia zhirnykh i dikarbonovykh kislot v mitokhondriiakh pecheni.

The functioning of the propionate pathway of oxidation substrate metabolism in the norm and under vitamin B12 deficiency has been studied. This pathway has been shown to play an important role in oxidative processes occurring in normal organisms, for its inhibition in B12-deficient animals is associated with a reduction of respiration as well as with noticeable decreases in palmitoylcarnitine and succinate oxidation rates and oxidation phosphorylation coupling. Succinate, the end product of the propionate pathway, normalizes the respiration and restores the rate of palmitoylcarnitine oxidation in B12-deficient animals, which is suggestive of its crucial role in the propionate pathway. In vivo propionate inhibits, whereas methyl malonate stimulates palmitoylcarnitine respiration, however only in intact animals. In B12-deficient animals the sensitivity to these metabolites is decreased.

[Properties of beta-carotene-15,15'-dioxygenase, stabilized during purification with lutein and dithiothreitol]. / Svoistva beta-karotin-15,15'-dioksigenazy, stabilirzirovannoi v protsesse vydeleniia liutenom i ditiotreitolom.

Preparations of beta-carotene 15,15'-dioxygenase (EC 1.13.11.21) obtained with or without lutein and dithiothreitol (DTT) as stabilizers display similar properties. The stabilized preparation has an apparent Km of 17 microM and Vmax of 2.8 nM/h/mg of protein, a pH optimum of 8.1, is sensitive to SH-agents and is activated by Fe2+, DTT or glutathione used at optimal concentrations of 0.5 mM, 2 mM, and 5 mM respectively. At DTT concentration above 2 mM the enzyme activity decreases drastically, which testifies to the importance of maintaining the thiol and disulphide group ratio in the protein molecule at an optimal level. At 4 mM Fe2+ there occurs a nonenzymatic formation of apo-carotenals; however, retinal is formed only after addition of commensurate amounts of thiol compounds. The enzyme activity depends on the ionic strength of the incubation medium, the maximal effect being observed with 0.4 M K-phosphate buffer. Substitution of phosphate for Cl- partly inhibits the enzyme. The optimal temperature for this reaction is 45 degrees. A simultaneous use of optimal incubation parameters (2 mM DTT, 0.4 M K-phosphate buffer pH 8.1 and 45 degrees C) increases the retinal yield 2.5-fold against control.

[Enzymatic conversion of torulene and torularhodine into retinal]. / Fermentativnoe prevrashchenie torulina i torularodina v retinal'.

The enzymatic conversion of torulene to retinal is demonstrated in in vitro tests using beta-carotene 15,15'-dioxygenase (EC 1.13.11.21) from the rabbit small intestine mucosa. This is the first evidence for the potent vitamin A activity of torulene. Little amounts of retinal also formed from methyl ester of torularhodin and from torularhodin.

[Effect of propionate pathway metabolites on the oxidative activity of liver mitochondria under normal conditions and in vitamin B12 deficiency]. / Vliianie metabolitov propionatnogo puti na okislitel'nuiu aktivnost' mitokhondrii pecheni v norme i pri nedostatochnosti vitamina B12.

We performed a comparative investigation in vivo and in vitro of the propionate and methylmalonate effect on oxidative activity of liver mitochondria in control and vitamin B12-deficient rats and found that efficiency of the effects were less pronounced in vitamin B12-deficient rats. It is also shown that the rates of respiration and phosphorylation decreased in liver mitochondria of vitamin B12-deficient rats.

[Stabilization and protection of an enzymatic system, participating in the transformation of beta-carotene into retinal, during its isolation]. / Stabilizatsiia i zashchita fermentnoi sistemy, uchastvuiushchei v orevrasgcgebuu v beta-karotina v retinal', pri ee vydelenii.

The authors studied the effect of dithiothreitol (DTT), carotenoids and protease inhibitors on stabilization and protection of the enzyme catalysing the conversion of beta-carotene into retinal during the enzyme isolation from the rabbit small intestine. The addition of 1 mM DTT into the homogenization mixture increased the activity of the enzyme 5 times compared with control. The additional introduction of 0.7 mg/ml soybean trypsin inhibitor or 2.10(-4) M phenylmethylsulfonyl fluoride increased the enzyme activity 2.1 and 1.2 times, respectively. Lutein, beta-carotene and lycopene at a concentration of 10 mg/ml increased the enzyme activity 2.1, 1.9 and 1.6 times respectively. The effects of DTT, lutein and the protease inhibitor depended on their concentrations and was of an independent additive character. The maximum activity of the isolated enzyme exceeded the control without DTT 15 times.

[Metabolism of S-methylmethionine (vitamin U) in animals]. / Metabolizm S-metilmetionina (vitamina U) u zhivotnykh.

Metabolism of S-methylmethionine (vitamin U) has been studied in rats. Biotransformation of this compound actively proceeds in the liver, kidneys, and digestive tract. Metabolism of S-methylmethionine in the liver and kidneys was found to proceed both via methylation of homocysteine with the formation of methionine and via enzymatic hydrolysis to dimethylsulfide and homoserine. In the digestive tract, only the activity of S-methylmethionine-sulphonium hydrolase was found. The physiological role of the metabolic routes under study is discussed.

[The effect of metabolites of the propionate pathway on the oxidative activity of liver mitochondria]. / Vliianie metabolitov propionatnogo puti na okislitel'nuiu aktivnost' mitokhondrii pecheni.

Methylmalonate and propionate, the major metabolites of the propionate pathway of fatty and amino acid metabolism used at 1-4 mM cause selective inhibition of succinate and palmitoyl carnitine oxidation in liver mitochondria. Methylmalonate is more specific towards succinate, whereas propionate--towards palmitoyl carnitine oxidation. Methylmalonate is transported to mitochondria at a high rate with no effect on succinate transport. Being injected intramusculary methylmalonate has no inhibiting effect on the oxidative activity of mitochondria but is able to activate succinate and palmitoyl carnitine oxidation. The inhibiting effect of propionate on palmitoyl carnitine oxidation is a long-term one. Injections of these metabolites precursors, isoleucine, methionine and valine, produce an activating effect on succinate oxidation. Thus, propionate pathway metabolites may participate in the regulation of lipid-carbohydrate metabolism.

[The effect of methylation on the carnitine synthesis]. / Vliianie protsessov metilirovaniia na sintez karnitina.

The effect of vitamin B12, its analogs and donors of methyl groups on the coupling of methylation and carnitine accumulation in rats was studied. Biological active forms of vitamin B12 (methylcobalamine, cyanocobalamine, hydroxycobalamine) are shown to stimulate the carnitine synthesis in liver. The donor of methyl groups S-methylmethionine, also has a positive effect. Factor B does not influence the carnitine level. The stimulating effect of vitamin B12 and donors in methyl groups on the carnitine synthesis seems to result from activation of methylation.

[Fluorescent immunoassay of thyroxine in blood serum]. / Fluorestsentnyi immunoanaliz tiroksina v syvorotke krovi.

A method of solid-phase fluoroimmunoassay of thyroxine (T4) on polystyrene 96-microtiter plates using coproporphyrin III-labeled antibodies was developed; 0.02 ml of blood serum without preliminary treatment was required. Thimerosal was added to lessen the T4-binding effect of the serum on the results of T4-binding effect of the serum on the results of the immunoassay. A calibration curve was obtained to determine T4 covering the entire physiological range of concentrations (from 3 to 21 micrograms of thyroxine in 100 ml of the serum). A variation coefficient within this range did not exceed 15%. For 14 unknown blood serum samples of patients the coefficient of correlation with the results obtained using a commercial kit for T4 determination (Abbott, USA) was 0.960. The time of the assay was 2-2.5 h. This method is simple and easy for use on a large scale.

[Effect of vitamin B12 on carnitine synthesis in the body of rats]. / Vliianie vitamina B12 na sintez karnitina v organizme krys.

The effect of vitamin B12 on carnitine metabolism in rats has been investigated. The injection of coenzyme B12 into male rats has been shown to result in the increase of carnitine in liver. The dynamics of this process and its dependence on the age of rats have been studied. A possible mechanism of anabolic action of vitamin B12 and carnitine is under discussion.