scholarly journals Relationship between alkaline phosphatase and neomycin formation in Streptomyces fradiae

1971 ◽  
Vol 122 (4) ◽  
pp. 397-404 ◽  
Author(s):  
Mrinal K. Majumdar ◽  
S. K. Majumdar
Keyword(s):  
Alkaline Phosphatase ◽  
Enzyme Activity ◽  
Phosphatase Activity ◽  
Sodium Nitrate ◽  
Inhibitory Effect ◽  
Enzymic Activity ◽  
Streptomyces Fradiae ◽  
Mineral Salts ◽  
Hydrolysis Of

Studies on phosphatase activity of Streptomyces fradiae 3535 grown in three different media indicate that neomycin formation varies directly with enzyme activity, sodium nitrate–maltose–mineral salts medium giving the highest yields of alkaline phosphatase and neomycin. S. fradiae contains more than one alkaline phosphatase and the phosphatase responsible for hydrolysis of neomycin phosphate appears to be substrate specific. The same enzyme apparently hydrolyses both the N–P and P–O–P bonds of neomycin pyrophosphate. The enzyme is stimulated by Ca2+, is inactive at a pH below 7 and is inhibited by EDTA. Enzymic activity increases when mycelia are incubated in mineral salts medium, but decreases when phosphate or glucose is included in the medium, although the latter is more effective. The inhibitory effect of EDTA on neomycin formation by resting mycelia is completely reversed by Ca2+.

scholarly journals Increase in alkaline phosphatase activity in calvaria cells cultured with diphosphonates

1979 ◽  
Vol 183 (1) ◽  
pp. 73-81 ◽  
Author(s):  
R Felix ◽  
H Fleisch
Keyword(s):  
Alkaline Phosphatase ◽  
Protein Synthesis ◽  
Enzyme Activity ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Heat Inactivation ◽  
High Concentration ◽  
Control Value ◽  
Km Value ◽  
Inhibitor Of Protein Synthesis

1. Dichloromethanediphosphonate and to a lesser degree 1-hydroxyethane-1,1-diphosphonate, two compounds characterized by a P-C-P bond, increased the alkaline phosphatase activity of cultured rat calvaria cells up to 30 times in a dose-dependent fashion. 2. Both diphosphonates also slightly inhibited the protein synthesis in these cells. 3. Thymidine, an inhibitor of cell division, did not inhibit the induction of the enzyme, indicating that the increase in enzyme activity was not due to the formation of a specific population of cells with high alkaline phosphatase activity. 4. The effect on alkaline phosphatase was suppressed by the addition of cycloheximide, an inhibitor of protein synthesis. 5. After subculturing the stimulated cells in medium without diphosphonates, the enzyme activity fell almost to the control value. 6. Bovine parathyrin diminished the enzyme activity of the control cells and the cells treated with dichloromethanediphosphonate; however, at high concentration the effect of parathyrin was greater on the diphosphonate-treated cells than on the control cells. 7. The electrophoretic behaviour, heat inactivation, inhibition by bromotetramisole or by phenylalanine, and the Km value of the induced enzyme were identical with that of the control enzyme.

Acid phosphatase, alkaline phosphatase, and nitrate reductase activity of selected ectomycorrhizal fungi

1989 ◽  
Vol 67 (3) ◽  
pp. 750-753 ◽  
Author(s):  
Iwan Ho
Keyword(s):  
Alkaline Phosphatase ◽  
Enzyme Activity ◽  
Acid Phosphatase ◽  
Nitrate Reductase ◽  
Phosphatase Activity ◽  
Ectomycorrhizal Fungi ◽  
Acid Phosphatase Activity ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Phosphatase Alkaline

Seventeen isolates, encompassing five genera and eight species of ectomycorrhizal fungi, were compared for acid phosphatase, alkaline phosphatase, and nitrate reductase activity. Isolates within species differed in enzyme activity and isozyme patterns by host specificity and site (as exemplified by the genus Suillus). Host and site may have affected phosphatase enzyme activity. Generally, the Douglas-fir associates, which dominate in mesic sites, have higher acid phosphatase activity than pine associates, which mostly occupy xeric sites; however, pine associates from mesic sites also have higher acid phosphatase activity (e.g., S. tomentosus). In four isolates of Amanita muscaria, the effect of site was also apparent. Two of them, which have significantly higher acid phosphatase activity than the others, were isolated from mesic sites. The isozyme pattern of the genus Suillus appeared to be separated by host groups. Other isolates with only one species also differed more or less by host groups. They shared at least one band within host groups, except for the two isolates of Paxillus involutus from different hosts. The P. involutus S-403 isolated from an orchard showed much higher nitrate reductase activity than all other isolates. No apparent differences in nitrate reductase activity were found between the other isolates.

Inhibitory effect of soil humic compounds on the proteolytic enzyme pronase

Soil Research ◽  
1969 ◽  
Vol 7 (3) ◽  
pp. 241
Author(s):  
JN Ladd ◽  
JHA Butler
Keyword(s):  
Humic Acids ◽  
Maximum Velocity ◽  
Kinetic Studies ◽  
Inhibitory Effect ◽  
Enzymic Activity ◽  
Humic Compounds ◽  
Km Value ◽  
Group Basis ◽  
Inhibitory Power ◽  
Hydrolysis Of

Neutralized solutions of soil humic acids inhibit the proteolytic activity of the enzyme pronase when tested against a variety of substrates. Protein hydrolysis was less sensitive than hydrolysis of dipeptide derivatives; 50% inhibition of benzyloxycarbonylglycylleucine hydrolysis was achieved with concentrations of humic acids as low as 1-2 �g/ml or less than 10-5M, on a carboxyl group basis. Humic acids, extracted from soils with different crop histories, showed only slight differences in their effectiveness as inhibitors of pronase activity. Their inhibitory power was comparable with that of other high molecular weight polyanions, e.g. polyacrylic acid and polycondensates derived from p-benzoquinone and catechol. Alginic acid was a relatively poor inhibitor. Preincubation of humic acids for various periods with either pronase or substrate (albumin or benzyloxycarbonylglycylleucine) had little or no effect on the subsequent inhibition of enzymic activity. However, inhibition is decreased by increasing substrate concentrations, following preincubation of humic acids and pronase. Both observations are consistent with a reversible inhibitory mechanism. Kinetic studies demonstrate that humic acids inhibit pronase activity towards albumin and N-benzyloxycarbonyl dipeptides by effectively reducing the affinity of pronase for the substrate, i.e. by increasing the Km value for the reaction. With benzoylarginine amide and benzoylarginine ethyl ester as substrates, the reaction velocity is lowered due to a reduction of the maximum velocity of the system. Both effects may possibly be explained by a conformational change in the enzyme structure due to combination with the humic acid molecules.

scholarly journals A Comparison of Human Leukocyte Phosphatase Activity toward Sodium β-Glycerophosphate, Adenosine 5'-Phosphate and Glucose 1-Phosphate

Blood ◽  
1959 ◽  
Vol 14 (4) ◽  
pp. 415-422 ◽  
Author(s):  
JAMES H. FOLLETTE ◽  
WILLIAM N. VALENTINE ◽  
JOHN REYNOLDS
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Cell Population ◽  
Alkaline Phosphatase Activity ◽  
Human Leukocyte ◽  
Maximal Activity ◽  
Phosphate Esters ◽  
Chronic Myelocytic Leukemia ◽  
Myelocytic Leukemia ◽  
Hydrolysis Of

Abstract The ability of human leukocyte enzymes to hydrolyze phosphorus is compared in terms of the conventional substrate sodium β-glycerophosphate and the metabolically important phosphate esters, adenosine 5'-phosphate and glucose 1-phosphate. At pH 9.9, there is marked and comparable variation in phosphatase activity toward all three substrates, this being low in chronic myelocytic leukemia and high in the presence of infection and certain "stressful" states. Moreover, substrate mixture experiments show no increased hydrolysis of phosphorus when two substrates are present in the incubation mixture. Increased phosphatase activity toward both glucose 1-phosphate and sodium β-glycerophosphate resulted when corticosteroids were administered in large doses for 72 hours. The data, while not providing absolute proof, are compatible with the hydrolysis of phosphorus at pH 9.9, being due in the case of all three substrates to the activity of the same phosphomonoesterase or group of phosphomonesterases. At pH 5.5, phosphatase activity toward both sodium β-glycerophosphate and adenosine 5'-phosphate was likewise demonstrated, but, in leukocytes, the pH of maximal activity varies from subject to subject and is dependent to a large extent on the amount of the highly variable "alkaline phosphatase" activity present in any given cell population at the time of analysis.

Polyphosphate body and acid phosphatase localization in Nostoc sp.

1984 ◽  
Vol 30 (1) ◽  
pp. 8-15 ◽  
Author(s):  
John D. DuBois ◽  
Keith R. Roberts ◽  
Lawrence A. Kapustka
Keyword(s):  
Enzyme Activity ◽  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Energy Stress ◽  
Nitrophenyl Phosphate ◽  
Carbon Compounds ◽  
Electron And Light Microscopy ◽  
Polyphosphate Bodies ◽  
Hydrolysis Of

Polyphosphate bodies and acid phosphatase activity were characterized in Nostoc sp. to determine if the hydrolysis of polyphosphate bodies occurs during dark (energy stress) periods. Electron and light microscopy were used to locate polyphosphate bodies. Acid phosphatase activity was measured using p-nitrophenyl phosphate as the substrate to determine net changes in the level of the enzyme activity. To induce energy stress, Nostoc sp. cells were kept in the dark for 72 h to deplete stored carbon compounds. Cells incubated in the light for 72 h (controls) showed acid phosphatase activity localized around the perimeter of polyphosphate bodies. When cells were incubated in the dark, acid phosphatase activity occurred throughout the polyphosphate body matrix. However, complete hydrolysis of the polyphosphate body did not occur and the rate of acid phosphatase activity was not affected.

Inhibition by concanavalin A as the basis for a specific assay of serum 5'-nucleotidase activity.

1977 ◽  
Vol 23 (12) ◽  
pp. 2311-2323 ◽  
Author(s):  
E R Zygowicz ◽  
F W Sunderman ◽  
E Horak ◽  
J F Dooley
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Concanavalin A ◽  
Significant Inhibition ◽  
Nucleotidase Activity ◽  
Hepatocellular Injury ◽  
Duct Ligation ◽  
The Difference ◽  
Hydrolysis Of

Abstract Concanavalin A inhibits serum 5'-nucleotidase activity, without causing significant inhibition of alkaline phosphatase activity. This observation serves as the basis for a new method for assaying the 5'-nucleotidase activity in serum, which depends upon the difference between the enzymic hydrolysis of adenosine-5'-monophosphate in the presence and absence of concanavalin A. A denosine released by the 5'-nucleotidase reaction is deaminated by a coupled reaction with adenosine deaminase to liberate inosine and ammonia, and ammonia is measured colorimetrically by the Berthelot reaction. In sera from 40 healthy adult persons, 5'-nucleotidase activity averaged 6.4 U/liter (SD, +/-2.0; range, 3-12). In sera from 100 patients, measurements of 5'-nucleotidase activity by the new assay averaged 8% lower than by a generally accepted method in which phenyl phosphate is used to suppress hydrolysis of adenosine-5'-monophosphate by alkaline phosphatase activity. The clinical validy of the new assay was tested by measuring serum 5'-nucleotidase activities in rats with bile duct ligation and in rats treated with thioacetamide to induce hepatocellular injury.

scholarly journals Induction of germ-cell alkaline phosphatase by butyrate and cyclic AMP in BeWo choriocarcinoma cells

1993 ◽  
Vol 296 (1) ◽  
pp. 59-65 ◽  
Author(s):  
J F Telfer ◽  
C D Green
Keyword(s):  
Alkaline Phosphatase ◽  
Enzyme Activity ◽  
Cyclic Amp ◽  
Germ Cell ◽  
Cholera Toxin ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Sodium Butyrate ◽  
Dibutyryl Camp ◽  
Choriocarcinoma Cells

BeWo choriocarcinoma cells synthesize two alkaline phosphatase isoenzymes: germ-cell alkaline phosphatase and tissue-unspecific alkaline phosphatase. We have made use of the differential heat-stabilities of these two isoenzymes to study the induction of germ-cell alkaline phosphatase by sodium butyrate and cyclic AMP (cAMP). Sodium butyrate causes a large induction of germ-cell alkaline phosphatase activity (approx. 35-fold after 96 h) after an initial lag period of 12-24 h. We showed that butyrate increases germ-cell alkaline phosphatase mRNA. Dibutyryl cAMP also induces germ cell alkaline phosphatase (approx. 2.5-fold after 96 h). When optimal concentrations of butyrate and dibutyryl cAMP were added simultaneously to cells, they caused a synergistic induction of activity. This suggested that these compounds use separate mechanisms to induce germ-cell alkaline phosphatase activity and that it is the cAMP moiety of dibutyryl cAMP that induces enzyme activity. This was confirmed by the use of two additional cAMP analogues, 8-(4-chlorophenylthio) cAMP and 8-bromo cAMP, and of two compounds, 3-methyl-1-isobutylxanthine and cholera toxin, which raise the endogenous concentration of cAMP. All four compounds caused a 2-fold increase in enzyme activity. Treatment of cells with 8-(4-chlorophenylthio) cAMP, 8-bromo cAMP and cholera toxin increased germ-cell alkaline phosphatase mRNA between 2- and 7-fold. These data suggest that this alkaline phosphatase isoenzyme is regulated at the level of its mRNA by cAMP, in a manner distinct from that of butyrate.

Studies on Leukocyte Phosphatases

1971 ◽  
Vol 17 (3) ◽  
pp. 210-213 ◽  
Author(s):  
Lawrence R DeChatelet ◽  
James V Volk ◽  
Charles E McCall ◽  
M Robert Cooper
Keyword(s):  
Amino Acids ◽  
Alkaline Phosphatase ◽  
Enzyme Activity ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Leukocyte Alkaline Phosphatase ◽  
Complete Reversal

Abstract The activity of leukocyte alkaline phosphatase is inhibited by a number of amino acids, most notably cysteine and histidine. The mechanism of this inhibition involves chelation of Zn2+ by the amino acids, as indicated by the complete reversal of the inhibition by added Zn2+. The concentrations of amino acids and Zn2+ required to affect the enzyme activity are such that their interaction might represent an in vivo mechanism for the control of leukocyte alkaline phosphatase activity.

Sign in / Sign up

Export Citation Format

Share Document