scholarly journals Measurement of 1-aspartamido-β-N-acetylglucosamine amidohydrolase activity in human tissues

1977 ◽  
Vol 163 (1) ◽  
pp. 9-14 ◽  
Author(s):  
B Dugal
Keyword(s):  
Enzyme Activity ◽  
Incubation Time ◽  
Human Liver ◽  
Enzyme System ◽  
Total Concentration ◽  
Reaction Times ◽  
Human Tissues ◽  
Human Organs ◽  
Crude Homogenate ◽  
Enzyme Fraction

The activity of 1-aspartamido-beta-N-acetylglucosamine amidohydrolase (aspartylglucosylaminase, EC 3.5.1.26) was measured in normal and diseased human liver, brain and kidney. Organs from patients with aspartylglucosaminuria show very little activity. Crude homogenates of human organs show a reaction catalysed by a complex enzyme system. With homogenate, the formation of product was linear with time up to about 6 h. Reaction times longer than 6-7h resulted in a decrease in the total concentration of product. This phenomenon was not found with the partially purified enzyme fraction. Linearity of the enzyme activity with different protein concentrations was found, independent of the incubation time. Longer incubation of the crude homogenate resulted in the utilization of the product, N-acetylglucosamine. This phenomenon was not observed with the partially purified enzyme fraction. This amidase from human organs differs from that obtained from other sources and apparently represents a rather complex enzyme system.

Xanthine Oxidoreductase Gene Expression and Enzyme Activity in Developing Human Tissues

Neonatology ◽  
1998 ◽  
Vol 74 (4) ◽  
pp. 274-280 ◽  
Author(s):  
Mika Saksela ◽  
Risto Lapatto ◽  
Kari O. Raivio
Keyword(s):  
Gene Expression ◽  
Enzyme Activity ◽  
Xanthine Oxidoreductase ◽  
Human Tissues

Inhibitory effect of six herbal extracts on CYP2C8 enzyme activity in human liver microsomes

Xenobiotica ◽  
2014 ◽  
Vol 45 (5) ◽  
pp. 406-412 ◽  
Author(s):  
Ahmed A. Albassam ◽  
Mohamed-Eslam F. Mohamed ◽  
Reginald F. Frye
Keyword(s):  
Enzyme Activity ◽  
Human Liver ◽  
Liver Microsomes ◽  
Inhibitory Effect ◽  
Human Liver Microsomes ◽  
Herbal Extracts

Determination of bromsulphthalein-glutathione conjugating enzyme activity in needle biopsy specimens of human liver

1973 ◽  
Vol 47 (2) ◽  
pp. 133-137 ◽  
Author(s):  
D.V. Datta ◽  
Sarban Singh ◽  
A.K.S. Samanta ◽  
S. Saha ◽  
M. Mukherjee ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Needle Biopsy ◽  
Human Liver ◽  
Biopsy Specimens ◽  
Conjugating Enzyme

Comparison of hydrolytic enzyme systems in pure culture and activated sludge under different electron acceptor conditions

1998 ◽  
Vol 37 (4-5) ◽  
pp. 335-343 ◽  
Author(s):  
Rajeev Goel ◽  
Takashi Mino ◽  
Hiroyasu Satoh ◽  
Tomonori Matsuo
Keyword(s):  
Enzyme Activity ◽  
Activated Sludge ◽  
Electron Acceptor ◽  
Bacillus Amyloliquefaciens ◽  
Enzyme System ◽  
Weak Link ◽  
Batch Reactor ◽  
Hydrolytic Enzyme ◽  
Hydrolytic Enzymes ◽  
Pure Cultures

Enzymatic hydrolysis under different electron acceptor conditions in nutrient removal activated sludge treatment processes is a weak link in the Activated Sludge Model no. 2 (Henze et al., 1995). An experimental study was undertaken to gain insight into the hydrolysis process with specific focus on hydrolysis kinetics and rates under different electron acceptor conditions. Two pure cultures, Bacillus amyloliquefaciens (Gram positive) and Pseudomonas saccharophila (Gram negative) were chosen for the study. In addition, activated sludge grown in an anaerobic-aerobic system was tested for enzymatic activity using starch as the model substrate. The hydrolytic enzymes were found to be released into the bulk in pure cultures whereas the enzyme activity was found to be mainly associated with the cell surfaces in activated sludge. Further, it was observed that the development of the hydrolytic enzyme system in Bacillus amyloliquefaciens and P. saccharophila is strongly suppressed under anoxic and anaerobic conditions. However, the effect of anaerobic and aerobic incubation on hydrolytic enzyme activity in activated sludge was found to be small. Starch hydrolysis kinetic data from batch experiments with activated sludge followed substrate saturation kinetics that were linear with biomass concentration. Finally, the similar hydrolytic enzyme activities observed under anaerobic and aerobic phases of a sequencing batch reactor are explained by considering the aspects of enzyme location and enzyme system development under aerobic and anaerobic phases. It is proposed that the floc bound enzymes are recycled in a single sludge system so that an equilibrium exists between enzyme loss and synthesis at steady state.

Stabilization of papain from papaya peels / Estabilización de la papaína de la cáscara de papaya

1998 ◽  
Vol 4 (3) ◽  
pp. 179-187 ◽  
Author(s):  
N. Espin ◽  
M.N. Islam
Keyword(s):  
Ascorbic Acid ◽  
Enzyme Activity ◽  
Protective Effect ◽  
Total Concentration ◽  
Sodium Ascorbate ◽  
Sodium Metabisulfite ◽  
Appreciable Effect ◽  
Original Activity ◽  
Before And After ◽  
Erythorbic Acid

Crude papain in papaya peels was stabilized before drying by the addition of various chemicals (ascorbic acid, sodium ascorbate, erythorbic acid, sodium erythorbate, sodium metabisulfite, sodium tetrathionate, 4-hexylresorcinol, t-butyl hydroquinone [TBHQ], rutin, α-tocopherol, trehalose, and sucrose). Chemicals were added to the ground papaya peels at 0, 0.12, 0.25, 0.5, 0.75, 1, 1.25, and 1.5% (w /w). Drying temperatures were 40, 55 and 60 °C. Enzyme activity was measured before and after drying by the casein digestion method. Percentage of enzyme activity retained (% EAR) was calculated by assigning a value of 100% EAR to fresh peels. Possible synergism between chemicals was also studied for a 1:1 ratio chemical/chemical at 1% total concentration. The highest % EAR was obtained at 55 °C for all chemicals except for sucrose and trehalose which showed their best effect at 40 °C. TBHQ rutin, α-tocopherol and 4-hexylresorcinol showed a destabilizing effect. Maximum protective effect occurred at 1% concentration. At this concentration sodium tetrathionate showed the best protective effect (90% EAR) followed by sodium metabisulfite (85% EAR), while both sodium ascorbate and sodium erythorbate retained 75% of the original activity. Ascorbic acid and erythorbic acid were 10% less effective than their corresponding sodium salts, possibly due to lower pH. Trehalose showed only 57 % EAR while sucrose failed to produce any appreciable effect. No synergistic effect was shown by any combination of chemicals.

scholarly journals N-Acetyl-β-d-hexosaminidase component A. Different forms in human tissues and fluids

1973 ◽  
Vol 135 (3) ◽  
pp. 457-462 ◽  
Author(s):  
J. U. Ikonne ◽  
R. B. Ellis
Keyword(s):  
Salt Concentration ◽  
Human Liver ◽  
Deae Cellulose ◽  
Minor Component ◽  
Human Tissues ◽  
Serum Enzyme ◽  
Hexosaminidase A ◽  
Minor Form ◽  
A Minor ◽  
Cellulose Column

1. Hexosaminidase A of human serum was resolved into two components, a minor form with properties identical with those of the single hexosaminidase A component of human liver, and a major form with significantly different properties. 2. The major serum hexosaminidase A form was eluted from a DEAE-cellulose column at a lower salt concentration than that required to elute the liver form. 3. A multiple-pass technique was used to elute the major serum enzyme A from a Sephadex G-150 column before that of liver enzyme A. 4. Clostridium perfringens neuraminidase converted the major component of serum hexosaminidase A into a form that was held less tightly by DEAE-cellulose, but the minor component of the A enzyme of serum, and the A enzyme of liver were not affected. 5. The hexosaminidase A from tears was similar to the A enzyme from serum, whereas those from several human tissues and from urine and lymph were similar to the liver form. 6. The A enzyme from serum may be derived from the A enzyme from liver by glycosylation before secretion.

scholarly journals Effect of different compounds on 1-aspartamido-β-N-acetylglucosamine amidohydrolase from human liver

1978 ◽  
Vol 171 (3) ◽  
pp. 799-802 ◽  
Author(s):  
B Dugal
Keyword(s):  
Enzyme Activity ◽  
Human Liver ◽  
Gel Filtration

The effect of varous compounds on 1-aspartamido-beta-N-acetylglucosamine amidohydrolase (aspartylglucosylaminase, EC 3.5.1.26) was studied. N-Acetylcysteine inhibited the nezyme non-competitively (Ki 3.2 mM), whereas 3-hydroxybutanone inhibited competitively (Ki 4.1 mM). Methionine, isoleucine and cystathionine apparently enhanced the enzyme activity. The enzyme had a mol. wt. of 63000 as determined by gel filtration. The present studies differentiate between the aspartylglucosylaminase from human liver and that obtained from various other sources.

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