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Biomedical subjects

A A Glemzha

Publications and source records attributed to A A Glemzha.

At least 19 recordsLinked to original sources
PubMed1987

[Interaction of NAD(H)-dependent dehydrogenases with active dyes and their complexes with transitional metal ions].

The interaction of NAD(H)-dependent dehydrogenases--yeast alcohol dehydrogenase and rabbit muscle lactate dehydrogenase--with reactive dyes produced in the USSR was studied. The essential role of metal ions in specific binding of alcohol dehydrogenase and dyes was demonstrated by differential spectroscopy, circular dichroism spectroscopy and chromatography. Lactate dehydrogenase in contrast with alcohol dehydrogenase does not require metal ions for the binding of the above-said dyes. A comparative study of eluting abilities of selected desorption agents (imidazole, adenine, 8-oxyquinoline-5-sulfonic acid, NAD, AMP, EDTA) by alcohol dehydrogenase chromatography on adsorbents with light-resistant yellow 2KT-Cu(II) and orange 5K revealed the differences in competition of the dyes for NAD-binding sites of alcohol dehydrogenase. The participation of light-resistant yellow 2KT-Cu(II) in the formation of mixed complexes with imidazole, adenine, 8-oxyquinoline-5-sulfonic acid, NAD and EDTA suggests that the specific binding of alcohol dehydrogenase to light-resistant yellow 2KT-Cu(II) is due to coordination between the Cu(II) ion and the amino acid residue in alcohol dehydrogenase.

Alcohol Dehydrogenase↗
PubMed1983

[Some properties of two forms of alpha-glucosidase from Saccharomyces cerevisiae-II].

The amino acid composition of two forms of alpha-glucosidase from the yeast Saccharomyces cerevisiae-II was established and the values of Km, V, kcat and kcat/Km for maltose, maltotriose and p-nitrophenyl-alpha-D-glucopyranoside (PNPG) were determined. PNPG possessed a much higher affinity for the enzyme as compared to sucrose, maltose and maltotriose. The value of V decreased in the following order: PNPG greater than sucrose greater than maltose greater than greater than maltotriose. No differences between the kinetic parameters of individual forms of alpha-glucosidase were observed. Glucose, fructose and methyl-alpha-glucoside act as competitive inhibitors. The two forms of alpha-glucosidase under study have an identical pH optimum and thermal stability.

Amino Acids↗
PubMed1981

[Isolation and properties of maltase from Saccharomyces cerevisiae-II].

Maltase from Saccharomyces cerevisiae-II was purified by ion-exchange chromatography on DEAE-Sephadex A-50 and isoelectric focusing. The purification procedure resulted in two enzyme isoforms with pI of 5.35 and 5.3 and identical specific activities. The molecular weights of the isoforms as determined by SDS polyacrylamide gel electrophoresis and gel filtration through Sephadex G-100 are 60 000 and 55 000, respectively. Both isoforms were electrophoretically polydisperse. The maltase isoforms are glycoproteins containing 1.5-2% of glucosamine and 5-8% (isoform A) and 2-3% (isoform B) of neutral sugars. Using paper chromatography and glucose oxidase, it was shown that glucose is an indispensable constituent of neutral sugars in both isoforms.

Carbohydrates↗
PubMed1978

[Acetate kinase chromatography on agarose derivatives].

Acetate kinase from E. coli K-12 was studied chromatographically on omega-aminoalkyl polysacharide sorbents. The dependence of the protein sorption-desorption on ionic strength and the effect of pH on the acetate kinase sorption were studied. The increase in the ionic strength caused a decrease in the amount of protein sorbed on the hexamethylenediamine- and chlorotriasinehexamethylenediamine sepharoses. On hexamethylenediamine-, octamethylenediamine- and dimethylhexamethylenediamine agaroses acetate kinase was adsorbed within the pH range of 6.5-9.0, whereas on the chlorotriasinehexamethylenediamine sepharose--at pH 6.5-8.0. The active protein was eluted at ionic strength of 0.14-0.17 M. Acetate kinase was not adsorbed on the carboxypropyonylaminohexyl sepharose within the pH range studied, i.e. 5.0-9.0 and was not adsorbed on hexamethylenediamine agarose at pH 4.0 and on chlorotriasinehexamethylenediamine sepharose--at pH 9.0. The mechanism of the enzyme-adsorbent interaction is discussed.

Acetates↗
PubMed1977

[Purification of phospholipase C from Bacillus cereus by chromatography on aminoalkylpolysaccharide adsorbents].

Purification of phospholipase C from Bac. cereus by chromatography on aminoalkylpolysaccharide adsorbents is described. The dependence of the degree of enzyme purification on the amount of ligant and effect of pH and buffer systems on the adsorption-desorption of phospholipase have been studied. At a pH below 9.0 phospholipase C is not retained by the adsorbents and is purified 4-5-fold and up to 23-fold, when aminoalkyl-Sepharose and hexamethylenediamine Sephadex are used respectively. With an increase in the pH value up to 10.0, the enzyme is bound by the adsorbent and is eluted with a 40-90% yield of activity and 7-10-fold purification. The resulting phospholipase C is highly purified and electrophoretically homogeneous. A mechanism of the enzyme-adsorbent interaction is discussed.

Adsorption↗
PubMed1977

[Isolation and some properties of phospholipase D from Bacillus subtilis G-22].

A method of isolating highly purified phospholipase D from Bac. subtilis G-22 is described. It includes ammonium sulphate fractionation, thermal denaturation, chromatography on lipoprotein bound with sepharose 6B and AH-sepharose 4B. The enzyme is 130-fold purified, its yield exceeds 90.0%, its specific activity is 164 units per mg of protein. The homogeneity of the enzyme is demonstrated by polyacrylamide gel electrophoresis, ultracentrifugation, isoelectric focusing and N-terminal amino acid determination by means of dinitrophenylation and dancylation. Proline is found to be N-terminal amino acid. The molecular weight of the enzyme, as determined from gel filtration through Sephadex G-100, is 21500 +/- 300, its sedimentation constant is 1.4S, isoelectric point is at pH 4.2. The molecular weight calculated from amino acid composition, is 21000--22000. Polypeptide chain contains of 196--205 amino acid residues. Phospholipase D develops its maximal activity at pH 8.5 and does not contain free SH-groups. Benzylsulphofluoride does not inhibit the enzyme activity. Phospholipase D is activated by Cd2+, Co2+, Zn2+, Ca2+ and is inhibited by EDTA, pIi50 being about 2.6.

Amino Acids↗
PubMed1976

[Purification and certain properties of pyruvate decarboxylase from bovine brain].

A procedure of isolation and purification of pyruvate decarboxylase (PDC) from bovine brain is worked out. 350-fold purified enzyme preparation was homogenous under polyacrylamide gel electrophoresis. Molecular weight of PDC from bovine brain was estimated to be 180 000 by means of gel chromatography through Sephadex G-200. The protein was eluted in two peaks (with molecular weight of 180 000 and 90 000 respectively). After the treatment of the enzyme preparation with 6 M guanidine chloride. Probably, partial dissociation of the enzyme molecule into two subunits takes place in this case. Data on paper chromatography confirmed that highly purified PDC preparations from bovine brain were isolated as apoenzyme, since they were almost free of TPP.

Animals↗
PubMed1976

[Serine proteases from Bac. subtilis].

Using biospecific adsorbent and subsequent gel-filtration of Sephadex G-75 three fractions of serine proteases (I--III) having different physicochemical properties were isolated from Bac. subtilis. The first protease had molecular weight of 23000--24000 (pH optimum 6,5, activation energy 16,6 ccal/mol. The second one had molecular weight of 29000, pH optimum 11,0, activation energy 14,4 ccal/mol. The third protease was a mixture of proteases with average molecular weights 26000 and pH optima at 7,0, 8,5 and 11,0.

Bacillus subtilis↗
PubMed1976

[Metal proteases from Bac. subtilis].

Metal and serine proteases were separated on the biospecific sorbent. Two different, homogeneous metal proteases were obtained by rechromatography of the metal protease. Activation energies, heat stability, molecular weights, influence of inhibitors, the dependence of activity on pH and temperature were determined. Properties of two metal proteases were compared with those of literary analogs.

Bacillus subtilis↗
PubMed1976

[Catalytic properties of alpha-ketoglutarate decarboxylase from bovine brain].

Investigation of the effect of different buffer systems on the rate of alpha-ketoglutarate decarboxylase reaction have shown that the pH optimum is 6.8 in tris-maleic, tris-H3PO4 and KH2PO4-KOH buffers, and it is 7.5 in imidazole buffer. The highest reaction rate was observed when using phosphate containing buffers. The increase of phosphate concentration increased considerably the rate of alpha-ketoglutarate decarboxylase reaction. Mg2+ and Ca2+ were shown to affect slightly the reaction rate. Co2+ and Ag+ slightly inactivated the enzyme. Cu2+ turned to be a very efficient inhibitor of alpha-ketoglutarate decarboxylase reaction. Apparent Mikhaelis constants are determined to be 1.6-10(-3) M for alpha-ketoglutaric acid and 1.7-10(-2)M for 2,6-dichlorphenolindophenol.

Animals↗
PubMedDate not supplied

[Method of purification of glucose oxidase by means of affinity chromatography on immunoabsorbent].

The possibility to purify glucose oxidase from Penicillium vitale on immunosorbent containing specific antibodies to the enzyme covalently bound with Sepharose 4B is studied. The method of affinity chromatography was applied, beside routine methods of fractionating blood serum proteins, to isolate specific antibodies from antiserum of rabbits immunized with glucose oxidase. Immobilized on Sepharose glucose oxidase was used as biospecific sorbent. Specific antibodies to the enzyme were isolated using chromatograpy of gamma-globulins mixture followed by protein desorption from the column with 1 M NaC1 and 3% glucose. Antibodies were immobilized by their covalent binding to activated Sepharose. The immunosorbent obtained was used to purify low active preparation of glucose oxidase by means of affinity chromatography under conditions worked out for the antibodies isolation. The enzyme was eluted from the column with 1 M NaC1 (pH 3.0) containing 3% glucose. 5-Fold purified enzyme preparation was isolated.

Binding Sites, Antibody↗
PubMedDate not supplied

[Phospholipase of Bacillus cereus].

Phospholipase activity of 10 strains of Bacillus cereus was studied. The most active strain of Bac. cereus--phospholipase producer was selected. A cultivation mixture of Bac. cereus optimal for the phospholipase synthesis was found to include peptone, yeast extract, glucose, NaCl and Na2HPO4. Proper conditions for the synthesis of phospholipase in flasks, 20 l and 250 l fermenters were tested. The maximum increase of the phospholipase activity occurred by the 5-9th hour of microbial growth at pH 6.0-8.0. Further cultivation, foaming, strong aeration, pH increase (over 8.0) reduced the accumulated activity. By fractionation with (NH4)2SO4, ethanol precipitation, protamine sulphate treatment with subsequent Sephadex G-100 gel filtration phospholipase (EC 3.1.4.3) was purified 300-fold from the culture liquid of Bac. cereus str. 504. The preparation was examined electrophoretically in 7% polyacrylamide gel at alkaline pH. The effect of metal salts and EDTA on phospholipase activity was studied. Thermostability, substrate specificity and pH optimum of purified phospholipase were investigated.

Bacillus cereus↗
PubMedDate not supplied

[Immobilization of urease from Staphylococcal saprophyticus L-1 on activated silica].

The paper deals with immobilization of urease obtained from Staphylococcus saprophyticus L-1 on the organic silica surfaces. The process completion time (4-5 h) and the optimal pH of binding (7-8) are practically independent of the chemical nature of the carrier surface. The value of the specific activity of urease grafted to silica depends not only on the type of the enzyme-carrier bond, but also on the macromolecule protein-to-silica distance. The extent of the retained enzyme activity is shown to be 26% after sorption on the initial silica. It grows to 100% with an increase of the organic radical length which separates the biocatalyst and the carrier.

Chemical Phenomena↗
PubMedDate not supplied

[Interaction of human albumin with sorbents containing immobilized dyes].

Interaction of human albumin with immobilized dye-adsorbents was investigated by frontal chromatographic analysis and static adsorption. The relative strength of the interaction is diminished in the following order: cibacron blue F3GA, orange 4K, claret CT, orange 5K, red-brown 2KT, light resistant yellow 2KT, bright blue KX, scarlet 2Zh, bright red 6C, bright yellow 53, red-brown 2K, golden yellow 2KX, scarlet 4ZhT and yellow 2KT. Following this order the absorbents can be used for purification of human albumin from non-specific impurities taking into account stronger adsorption of albumin or impurities. Adsorbents with dyes immobilized on macroporous silica were found to be promising for large-scale purification of human albumin. The silica adsorbent containing red brown 2K is effective for the removal of the following impurities from placental albumin: chorionic gonadotropin, alpha-fetoprotein and placental lactogen.

Binding Sites↗
PubMedDate not supplied

[Properties of the phospholipases C from Bacillus cereus].

Three different phospholipases C--the so-called phospholipase C which hydrolyses phosphatidylcholine (Pch-PLC), sphingomyelinase (SM-PLC) and phosphatidylinositol hydrolysing phospholipase C (PI-PLC)--were separated from the culture filtrate of Bacillus cereus using column chromatography on DEAE-sephadex A-50. The pI values were estimated to be 5.0 +/- 0.3 for PI-PLC and 5.3 +/- 0.2 for SM-PLC. The effect of some bivalent cations was studied. Metal ions had no effect on the activity of PI-PLC, whereas Mg2+ and Co2+ in concentrations from 1 to 5 mM highly activated SM-PLC. Mg2+ failed to activate PCh-PLC, and Co2+ even inhibited it. EDTA of o-phenantroline had a rather inhibitory effect on Pch-PLC, but they almost did not affect SM-PLC.

Animals↗