[The pre- and posttranslational regulation of the enzymes participating in glycogen phosphorolysis]. / Pre- i posttransliatsionnaia reguliatsiia fermentov, uchastvuiushchikh v fosforolize glikogena.

The analysis of published and own experimental data concerning function of enzymes of glycogen phosphorolysis is presented. Various types of inherited disorders in glycogen degradation are considered. The necessity of the complex approach to the investigation of enzymopathies mentioned with application of the advanced biochemical and genetical methods for more exact diagnostics and effective treatment is emphasized.

[The effect of alloxan on activity of various enzymes of phosphorus metabolism in vitro]. / Vliianie alloksana in vitro na aktivnost' nekotorykh fermentov fosfornogo obmena.

Effect of alloxan on activity of acetylphosphatase, alkaline and acid phosphatases, phenylpyrophosphatase was studied in vitro. Alloxan at concentrations 100 microM-10 mM inhibited acid phosphatase and especially alkaline phosphatase. Reducing agents (pyrocatechol, hydroquinone, ascorbic acid), which are easily converted into corresponding oxidized forms, at concentrations 100 microM-1.0 mM activated alkaline phosphatase in rat kidney and small intestine.

[Phosphoprotein phosphatase of the myocardium. Isolation of individual molecular forms and their regulation]. / Fosfoproteinfosfataza serdechnoi myshtsy. Vydelenie otdel'nykh molekuliarnykh form i ikh reguliatsiia.

Individual molecular forms of phosphoprotein phosphatase (PPase) and their inhibitors of the protein nature were isolated from rat heart muscle by means of column chromatography on DEAE Sephadex A-50. All the three fractions of PPase were capable to dephosphorylate casein but did not affect pyrophosphate. PPase I dephosphorylated trimethaphosphate or casein. The enzyme molecular forms were different from each other by the value of specific activity and sensitivity to heat treatment. Two protein inhibitors eluted by buffers of different ionic strength - 0.2 M and 1.6 M - were identified. One of them was inactivated during heat treatment (95 degrees 5 min), while the second inhibitor maintained completely its activity in these conditions.

[Effect of trihydroxyoctadecadiene acids from Bryonia alba L. on the activity of glycogen metabolism enzymes in alloxan diabetes]. / Vliianie trioksioktadekadienovykh kislot iz Bryonia alba L. na aktivnost' fermentov obmena glikogena pri alloksanovom diabete.

It was shown previously in experiments on white rats with alloxan diabetes that trihydroxyoctadecadiene acids from Bryonia alba L. have a hypoglycemic action. The present paper is concerned with the effects of the above-indicated compounds on the activity of glycogen phosphorylase (a- and b-forms), phosphoprotein phosphatase and hexokinase in liver and muscle tissues of white rats with alloxan diabetes. One of the possible mechanisms of the hypoglycemic action of trihydroxyoctadecadiene acids is discussed.

[Use of isofocusing for isolating and characterizing phosphorus metabolism enzymes]. / Ispol'zovanie izofokusirovaniia dlia vydeleniia i kharakteristiki fermentov fosfornogo obmena.

A modified procedure is described for colorimetric estimation of phosphate in a sample containing ampholines; the procedure enabled to simplify the detection of some enzymes of phosphorus metabolism in the fractions obtained after isoelectric focusing of the initial protein mixture. The analyses did nor require an isotope technique and dialysis and were carried out within a relatively short period.

[Separation of fractions of phosphoprotein phosphatase and its protein inhibitors by isoelectrofocusing]. / Razdelenie fraktsii fosfoproteinfosfatazy i eë belkovykh ingibitorov metodom izoelektrofokusirovaniia.

Individual molecular forms of phosphoprotein phosphatase from albino rat cardiac muscle were separated by isoelectrofocusing, resulting in a few fractions differing in pI (5.1, 5.4, 5.9-6.1 (double peak) and 7.1, respectively). Isoelectrofocusing of a purified enzyme preparation also allowed to isolate and characterize two protein inhibitors of the enzyme. The first one with pH 6.5-6.7 is similar to the thermostable phosphoprotein phosphatase inhibitor known from literature. This protein inhibits the enzyme activity by 90%; its effect is not decreased after 5-min heating at 95 degrees. The other inhibitor protein with pH 5.6-5.8 is thermolabile. When the enzyme activity was decreased 2.5-fold prior to thermal treatment, the latter protein lost this ability after heating at 95 degrees and inhibited the enzyme only by 9%. It is assumed that inhibitory proteins beside low molecular weight effectors can be involved in the mechanisms of the post-synthetical operative modification of phosphoprotein phosphatase function.

[Molecular mechanisms of hypothalamic hexapeptide regulation of the links in glycogen metabolism]. / Molekuliarnye mekhanizmy reguliatsii gipotalamicheskim geksapeptidom nekotorykh zven'ev obmena glikogena.

Alterations in content of glycogen as well as in activity of phosphorylase and phosphoprotein phosphatase were studied in various rat tissues after intravenous administration of a new hypothalamic hexapeptide Tyr-Gly-Leu-Pro-Gly-NH2. An increase in phosphoprotein phosphatase activity was observed in heart muscle, which correlated with transformation of phosphorylase A to the B form and with accumulation of glycogen. The opposite effect was found in liver tissue and sceletal muscle.

[Participation of some nucleotides in regulation of phosphoprotein phosphates activity in rat and chicken myocardium]. / Uchastie nekotor'kh nukleotidov v reguliatsii fosfoproteinfosfataznoi aktivnosti v serdechnoi myshtse krys i kur.

Adenine- and uridine di- and triphosphates (in a 3 mM concentration) increase considerably phosphoprotein phosphatase (PPPase) (EC 3.1.3.16) activity of rat and chicken myocardium homogenates. AMP and Pi are effective inhibitors of the enzyme. The ATP activating effect is also shown in partially purified preparations of rat myocardium PPPase. ATP is able of protecting significantly the enzyme during its thermodenaturation.