The influence of time, temperature, pH and calcium carbonate on the activity of the phytase of certain cereals

1954 ◽  
Vol 44 (3) ◽  
pp. 306-310 ◽  
Author(s):  
R. Hill ◽  
C. Tyler
Keyword(s):  
Calcium Carbonate ◽  
Sodium Bicarbonate ◽  
Wheat Bran ◽  
Considerable Degree ◽  
Ph Values ◽  
Optimum Ph ◽  
Rate Of Hydrolysis ◽  
Phytate Hydrolysis ◽  
Soluble Substrate ◽  
Hydrolysis Of

1. Tests have been carried out to investigate the hydrolysis of phytate in wheat, bran, and oats.2. Oats showed practically no phytase activity.3. Wheat phytase had an optimum pH of 5·0–5·1 and functioned at pH values down to 3·0. When hydrolysis had been arrested by acidifying to pH 2·5 for 5 min. or longer, the phytase did not recover when the pH was raised to 5·0 by the addition of sodium bicarbonate.4. There was an almost uniform increase in the rate of hydrolysis between 15 and 50° C.5. The rate of phytate hydrolysis decreased as the reaction proceeded, but the reaction continued until only a very small amount of soluble substrate remained.6. The presence of calcium, under conditions in which it could form insoluble phytate, reduced phytate hydrolysis to a considerable degree.7. These reactions are considered in relation to phytate hydrolysis in the digestive tracts of animals.

scholarly journals Phosphatase synthesis in Klebsiella (Aerobacter) aerogenes growing in continuous culture

1972 ◽  
Vol 127 (1) ◽  
pp. 87-96 ◽  
Author(s):  
P. G. Bolton ◽  
A. C. R. Dean
Keyword(s):  
Alkaline Phosphatase ◽  
Acid Phosphatase ◽  
Continuous Culture ◽  
Activity Profile ◽  
Glucose Effect ◽  
Ph Values ◽  
Nitrophenyl Phosphate ◽  
Wide Range ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

1. Phosphatase synthesis was studied in Klebsiella aerogenes grown in a wide range of continuous-culture systems. 2. Maximum acid phosphatase synthesis was associated with nutrient-limited, particularly carbohydrate-limited, growth at a relatively low rate, glucose-limited cells exhibiting the highest activity. Compared with glucose as the carbon-limiting growth material, other sugars not only altered the activity but also changed the pH–activity profile of the enzyme(s). 3. The affinity of the acid phosphatase in glucose-limited cells towards p-nitrophenyl phosphate (Km 0.25–0.43mm) was similar to that of staphylococcal acid phosphatase but was ten times greater than that of the Escherichia coli enzyme. 4. PO43−-limitation derepressed alkaline phosphatase synthesis but the amounts of activity were largely independent of the carbon source used for growth. 5. The enzymes were further differentiated by the effect of adding inhibitors (F−, PO43−) and sugars to the reaction mixture during the assays. In particular, it was shown that adding glucose, but not other sugars, stimulated the rate of hydrolysis of p-nitrophenyl phosphate by the acid phosphatase in carbohydrate-limited cells at low pH values (<4.6) but inhibited it at high pH values (>4.6). Alkaline phosphatase activity was unaffected. 6. The function of phosphatases in general is discussed and possible mechanisms for the glucose effect are outlined.

HYDROLYSIS OF GLYCEROLPHOSPHATIDES BY PLASTID PHOSPHATIDASE C

1956 ◽  
Vol 34 (5) ◽  
pp. 967-980 ◽  
Author(s):  
Morris Kates
Keyword(s):  
Ethyl Ether ◽  
Phosphatidyl Choline ◽  
Phosphatidyl Ethanolamine ◽  
Enzymatic Reaction ◽  
Phosphatidyl Serine ◽  
Ph Optimum ◽  
Soybean Phosphatide ◽  
Optimum Ph ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

Studies of the influence of structural variation in the glycerolphosphatide molecule on the hydrolysis of this class of compounds by plastid phosphatidase C showed that the presence of both fatty acid ester groups is necessary for enzymatic reaction; that release of nitrogenous bases occurred, in the presence of ethyl ether, from phosphatidyl cholines, phosphatidyl ethanolamine, and phosphatidyl serine; and that a phosphatidyl choline was hydrolyzed more rapidly than the corresponding phosphatidyl ethanolamine or phosphatidyl serine. The rate of hydrolysis of phosphatidyl choline was influenced greatly by the chain length and degree of unsaturation of the fatty acids. The corresponding phosphatidic acid formed in the hydrolysis of (dipalmitoyl)- or (dipalmitoleyl)-lecithin by carrot phosphatidase C was isolated. Studies on the hydrolysis of crude soybean phosphatide by phosphatidase C showed that both choline and ethanolamine were liberated in the absence of ethyl ether, at an optimum pH of 4.8; in the presence of ether, the rate of liberation of each base was increased, and the pH optimum was between 4.8 and 6. Soybean phosphatide probably contains a substance that stimulates the enzymatic hydrolysis.

HYDROLYSIS OF GLYCEROLPHOSPHATIDES BY PLASTID PHOSPHATIDASE C

1956 ◽  
Vol 34 (1) ◽  
pp. 967-980 ◽  
Author(s):  
Morris Kates
Keyword(s):  
Ethyl Ether ◽  
Phosphatidyl Choline ◽  
Phosphatidyl Ethanolamine ◽  
Enzymatic Reaction ◽  
Phosphatidyl Serine ◽  
Ph Optimum ◽  
Soybean Phosphatide ◽  
Optimum Ph ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

Studies of the influence of structural variation in the glycerolphosphatide molecule on the hydrolysis of this class of compounds by plastid phosphatidase C showed that the presence of both fatty acid ester groups is necessary for enzymatic reaction; that release of nitrogenous bases occurred, in the presence of ethyl ether, from phosphatidyl cholines, phosphatidyl ethanolamine, and phosphatidyl serine; and that a phosphatidyl choline was hydrolyzed more rapidly than the corresponding phosphatidyl ethanolamine or phosphatidyl serine. The rate of hydrolysis of phosphatidyl choline was influenced greatly by the chain length and degree of unsaturation of the fatty acids. The corresponding phosphatidic acid formed in the hydrolysis of (dipalmitoyl)- or (dipalmitoleyl)-lecithin by carrot phosphatidase C was isolated. Studies on the hydrolysis of crude soybean phosphatide by phosphatidase C showed that both choline and ethanolamine were liberated in the absence of ethyl ether, at an optimum pH of 4.8; in the presence of ether, the rate of liberation of each base was increased, and the pH optimum was between 4.8 and 6. Soybean phosphatide probably contains a substance that stimulates the enzymatic hydrolysis.

428. The acid phosphatase of mammary tissue of the cow and the rat

1950 ◽  
Vol 17 (3) ◽  
pp. 306-311 ◽  
Author(s):  
J. E. C. Mullen
Keyword(s):  
Alkaline Phosphatase ◽  
Acid Phosphatase ◽  
Replacement Therapy ◽  
Marked Effect ◽  
Mammary Tissue ◽  
Optimum Ph ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

1. Mammary tissue of the cow and the rat contains acid phosphatase. The respective pH optima are 5·5–5·8 and 6·0.2. The enzyme in cow mammary tissue is probably one of type AII in the Folley & Kay (10) classification.3. The acid phosphatase of cow mammary tissue is inhibited by a factor in raw cows' milk. This factor is destroyed by heat.4. On the basis of rate of hydrolysis of phenylphosphate at the optimum pH there is about 5 times more alkaline phosphatase in the mammary tissue of the cow than acid phosphatase.5. The effect of adrenalectomy and replacement therapy through the administration of cortical steroids has no marked effect on the acid phosphatase of rat mammary tissue.

ACID PHOSPHATASE HYDROLYSIS OF PHOSPHORIC ESTERS

1955 ◽  
Vol 33 (1) ◽  
pp. 539-544 ◽  
Author(s):  
G. E. Delory ◽  
G. S. Wiberg ◽  
Merle Hetherington
Keyword(s):  
Acid Phosphatase ◽  
Seminal Fluid ◽  
Optimum Ph ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

The rate of hydrolysis and optimum pH of hydrolysis of seminal fluid acid phosphatase have been studied for a number of phosphoric esters. As the acidity of the substrate increases there is a tendency for the rate of hydrolysis to increase and for the optimum pH to move farther away from neutrality. The increased rate of hydrolysis of phenol phosphates or of substituted phenol phosphates can not be accounted for by phenolase activity.

scholarly journals Synthesis of Biopolymers by Condensed Histidine Imide Derivatives with Some Acid Anhydride and Their Crosslink with Acrylonitrite

2014 ◽  
Vol 5 (1) ◽  
pp. 27-41
Author(s):  
Dr. Firyal. M.A ◽  
Assel K. M.
Keyword(s):  
Chemical Resistance ◽  
Basic Medium ◽  
Direct Polycondensation ◽  
Visible Spectroscopy ◽  
Bioactive Polymers ◽  
Ph Values ◽  
Ft Ir ◽  
Rate Of Hydrolysis ◽  
Uv Visible ◽  
Hydrolysis Of

Histidine as known amino acid was converted to its acid chloride [C1] with thionyl chloride at 0 oC, then reacted with ammonia, the corresponding imide-diamine [C2] was obtained, and then condensed with maleic or methylnadic anhydride. The two novel condensed polymers [C3, C4] were obtained with highly conversion percentage and modified to crosslinked polymers [C5, C6] with acrylonitrile monomer through vinylic group by free radical polymerization. The physical properties of all prepared polymers were studied and characterized by 1H-NMR, FT-IR and UV-visible spectroscopy. The swelling % was calculated. The new Polymers [C3, C4], were synthesized by direct polycondensation to give the new bioactive polymers. The rate of hydrolysis of the prepared polymers was studied in different pH values at 37 oC. Howeve, the crosslinked biopolymers [C5, C6] indicated much more chemical resistance than [C3, C4], and the sustained release was observed as good results in basic medium.

EFFECT OF pH, CALCIUM CONCENTRATION AND TEMPERATURE ON THE HYDROLYSIS OF DICALCIUM PHOSPHATE DIHYDRATE

1989 ◽  
Vol 69 (3) ◽  
pp. 689-693 ◽  
Author(s):  
G. W. MORDEN ◽  
G. J. RACZ
Keyword(s):  
Key Words ◽  
Calcium Concentration ◽  
Dicalcium Phosphate ◽  
Dicalcium Phosphate Dihydrate ◽  
Effect Of Ph ◽  
Ph Values ◽  
Phosphate Dihydrate ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

The rate of hydrolysis of DCPD to OCP in solutions of different pH values, calcium concentrations and temperatures was studied. Rates of hydrolysis were very slow at pH 6.0, relatively rapid and similar at pH 7.0 and 8.0, much slower at 10 °C than at 20 or 30 °C, and only slightly increased by increasing calcium concentration. Key words: Dicalcium phosphate dihydrate, hydrolysis, pH, temperature, calcium concentration

An extracellular proteolytic enzyme from Scopalariopsis brevicaulis. II. Hydrolysis of poly amino acids

1972 ◽  
Vol 18 (7) ◽  
pp. 1165-1167 ◽  
Author(s):  
Kartar Singh ◽  
Claude Vézina
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Proteolytic Enzyme ◽  
Ph Values ◽  
Optimum Ph ◽  
Extracellular Proteolytic Enzyme ◽  
Scopulariopsis Brevicaulis ◽  
Hydrolysis Of

Scopulariopsis brevicaulis protease hydrolyzed poly-L-lysine and poly-L-glutamic acid; optimum pH values for hydrolysis were 10.6 and 4.7 respectively. Final products of poly-L-lysine digestion by the protease were intermediate peptides from tetramer upwards. Pentalysine was not hydrolyzed by the enzyme. The protease had no action on poly-L-aspartic acid, poly-L-alanine, poly-L-glycine, poly-L-valine, or poly-L-leucine.

ACID PHOSPHATASE HYDROLYSIS OF PHOSPHORIC ESTERS

1955 ◽  
Vol 33 (4) ◽  
pp. 539-544 ◽  
Author(s):  
G. E. Delory ◽  
G. S. Wiberg ◽  
Merle Hetherington
Keyword(s):  
Acid Phosphatase ◽  
Seminal Fluid ◽  
Optimum Ph ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

The rate of hydrolysis and optimum pH of hydrolysis of seminal fluid acid phosphatase have been studied for a number of phosphoric esters. As the acidity of the substrate increases there is a tendency for the rate of hydrolysis to increase and for the optimum pH to move farther away from neutrality. The increased rate of hydrolysis of phenol phosphates or of substituted phenol phosphates can not be accounted for by phenolase activity.

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