Sanaa T. El-Sayed

Sanaa T. El-Sayed
National Research Center, Egypt | NRC · Department of Biochemistry

Prof. Dr. of Biochemistry

About

78
Publications
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346
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November 1975 - February 2017
National Research Center, Egypt
Position
  • Ex head of Biochemistry Department

Publications

Publications (78)
Article
The aim of the present study was to prepare novel monophenolase inhibitory peptides from Vicia faba (broad bean) pods. Isolated protein was hydrolysed by immobilized protease at pH 10. For maximum production of hydrolysate (peptides), an optimized hydrolysis process, including incubation temperature and protein concentration, was established. Broad...
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The present study was designed to prepare a novel tyrosinase inhibitory peptides from Solunum tuberosum (potato) peels (by-product of potato processing). Isolated protein was hydrolyzed by immobilized lettuce protease at pH 10 to produce a potato hydrolysate (peptides) with the highest tyrosinase inhibitory activity than that of the parent protein....
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patients after surgery of urinary calculi from Kasr El Ainy hospital.The stones were treated with 60% solution of green tea for 7 days at 370 with rotating. The dried stones were analyzed by energy-dispersive X-ray spectroscopy (EDX) instrument. Results: Figures 1&2 are taken for MAP stone sample number 5 (S5) before and after treatment with green...
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The aimed of this work, was improved the stability of the chitosanase enzyme by immobilization with different natural carriers to enhance the economic of industrial biocatalytic process. It was used in preparation of biological active chitooligosaccharides. Pepper chitosanase extracted from (Capsiuum annuum) leaves was immobilized by four different...
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Our work was designed to evaluate antioxidant (free radical scavenging and reducing power) and cytotoxicity activities of chitooligosaccharides with different molecular weights. The antioxidant activities in vitro were assessed by three separated methods, including DPPH (1,1-diphenyl-2-picrylhydrazyl radical) and ABTS (2,2-azinobis (3-methyl-benzot...
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Kinetic properties and stability studies of pepper chitosanase immobilized on chitin by covalent bond for production of chitooligosaccharides was the main objective of this work. A comparison with the properties that shown by the free one was also carried out. Maximum enzyme activity was observed at 2.825 and 0.576 mg chitosan /reaction mixture for...
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Chitosan has antimicrobial activities against a wide range of food-borne microorganisms. It was poorly soluble in neutral solution, which makes them difficult to use in food and biomedical applications. While chitooligosaccharides were fairly soluble in aqueous solution and consequently facilitated their utilization in industrial application. There...
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Characterization and kinetics studies of immobilized pea (Pismus sativum) invertase immobilized by entrapment in alginate beads was the main objective of this work. Immobilized pea invertase catalyzed hydrolysis of sucrose to invert sugar (glucose and fructose). It showed high specific activity (243.3 U/mg) under optimization working conditions...
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The present study aimed to evaluate the production of high fructose syrup (invert sugar) HFSb and HFSc from sugar beet and chicory roots, respectively, using immobilized pea invertase and compare it with that produced from sucrose and inulin. Immobilized pea invertase showed maximum specific activity (251.2 and 225.0 U/mg) towards sugar isolates fr...
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The aim of this study was to prepare immobilized protease with high hydrolytic activity for biotechnological applications. Lettuce seeds (Lactuca sativa) were used for extraction of alkaline protease using tris-buffer, pH 5 as enzyme solvent. High yield of alkaline protease (35.9 U/g wt. dry seeds) was obtained. The biochemical properties of the pr...
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The products of chitosan hydrolysis are chitooligosaccharides and are used mainly for medical applications due to their specific biological activities. The objective of this study was to prepare and separate chitooligosaccharides (COSN)from chitosan using Capsicum annuum immobilized chitosanase. We firstly studied the optimal reaction conditions...
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The products of chitosan hydrolysis are chitooligosaccharides and are used mainly for medical applications due to their specific biological activities. The objective of this study was to prepare and separate chitooligosaccharides (COSN)from chitosan using Capsicum annuum immobilized chitosanase. We firstly studied the optimal reaction conditions, i...
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Free chitosanase CN, the ammonium sulphate fraction precipitated from crude pepper chitosanase, was immobilized on chitin by using physical adsorption and covalent binding methods. We developed chitosanase immobilized on chitin by adsorption methods for 2 and 24 hat different pHs values from 5.4 to 8.0.The optimal condition for chitosanase immobili...
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The aim of this study was to test the possible presence of potent invertase enzyme with promising industrial application in local low cost Egyptian plants. Pismussativum pods (pea pods) were chosen for further study as it shows highest invertse activity (82%U/g dry weight tissues) among the screened plants. Invertase enzyme was extracted with disti...
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The aim of this study was to prepare immobilized invertase with high hydrolytic activity for biotechnological applications. Pea invertase was immobilized in alginate beads using 2% sodium alginate. Optimization condition of entrapped free invertase in sodium alginate was investigated. Immobilized process depends on the amount of free enzyme added a...
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Brassica napus (rape) seeds were chosen as source for milk-clotting activity (MCA). The extract shows the most potent clotting activity (164 U/g dry seeds) with firm clotting with the minimum proteolytic activity at pH 4.5. The purification scheme for milk-clotting enzyme (MCE) included precipitation with (NH 4) 2 SO 4 (20-60%-saturation) followed...
Article
Abstract: Citrus processing by-products represent a rich source of natural occurring flavonoids (hesperidin) and polymethoxylated flavones (nobiletin and tangeritin) which have been of intense interest for their pharmacological properties. Little attention has been given to the isolation of these flavonoids in peel and to the possibility of recover...
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Purification of three chitosanases (A 1 , A 2 and A 3) from Capsicum annuum (pepper) leaves extract was done with different techniques giving three isoenzymes named A 1 , A 2 and A 3 with specific activities of 107.3±6.9, 57.8±0.1 and 81.1±0.0 U/mg protein, respectively. The enzymes were purified about 66.2, 35 and 49 fold by three chromatographic...
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Full-text available
Citrus processing by-products represent a rich source of natural occurring flavonoids (hesperidin) and polymethoxylated flavones (nobiletin and tangeritin) which have been of intense interest for their pharmacological properties. Little attention has been given to the isolation of these flavonoids in peel and to the possibility of recovering flavon...
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The aim of this study is to test the possible presence of different proteolytic enzymes with promising industrial application in local low cost plant seeds. The aqueous extracts of 28 dry seeds representing eight families (Cruciferae, Umbelliferae, Leguminosae, Rosaceae, Asteraceae, Gramineae, Tiliaceae, and Cucurbitaceae) were screened in order to...
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Abstract: Bean (Vicia faba) and white kidney bean (Phaseoulus vulgaris) seeds were selected from a screening programmed for L- asparagine hydrolysis by L- asparaginase. These seeds were immobilized successfully by simple adsorption on tricalcium phosphate, active carbon, silica gel and carboxmethyl cellulose powder. The best support for bean L- asp...
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Abstract: The present study was conducted to investigate the lipid-lowering and antioxidative activities of aqueous garlic extract (AGE, 1 ml/Kg, orally, corresponding to 500 mg/Kg/ day) in heart and liver tissues of rabbits fed with high-cholesterol diet. Twenty-eight male white New Zealand rabbits were divided into four groups, 7 rabbits each. Th...
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Bean (Vicia faba) and white kidney bean (Phaseoulus vulgaris) seeds were selected from a screening programmed for L- asparagine hydrolysis by L- asparaginase. These seeds were immobilized successfully by simple adsorption on tricalcium phosphate, active carbon, silica gel and carboxmethyl cellulose powder. The best support for bean L- asparaginase...
Article
Full-text available
The aim of this study was to test the possible presence of potent milk-clotting enzymes with promising industrial application in local low cost Egyptian plant seeds. The aqueous extracts of 28 dry seeds representing eight families (Cruciferae, Umbelliferae, Leguminosae, Rosaceae, Asteraceae, Gramineae, Tiliaceae, and Cucurbitaceae) were screened in...
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L-asparagine deamidating enzyme from Penicillium politans NRC510 was purified by a simple method of heat-ing and Sephadex G-100 gel filtration. These procedures yield the partially purified enzyme with 30% recovery of the activity in crude extracts. Specific activity of this par-tially enzyme is 166 IU/mg. The enzyme hydrolyzes L-as-paragine, D-asp...
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Isolation and characterization of a chitosanase enzyme with high activity from different parts of some higher plants were studied. Different vegetative plant parts (leaves, fruit peels and dried seeds) representing nine families were screened in order to select the best source for extraction of the chitosanase enzyme. Results of screening experimen...
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L-asparaginase is one of the known drugs in the treatment of cancer, especially acute lymphoblastic leukemia. In recent years several bio-conjugation protocols have been developed to improve the pharmacokinetic and immunological properties of anti-leukemic enzyme, L-asparaginase. In this study, fifty two bacilli species were newly isolated in our l...
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Zea mays (maize) leaves (I) and Opuntia tuna (prickly pears) peels (II) were selected as a source of protease enzymes from a programmed screening for casein hydrolysis. These 2 crude enzymes were partially purified by ammo-nium sulphate fractionation and gel filtration on Sephadex G-100 columns. They were purified to final specific activity of 2093...
Article
Two fibrinolytic enzymes isolated from B. subtilis and from B. polymyxa were purified using a five step method. The pH optimum for the enzyme from B. subtilis was 7.2 and for the enzyme from B. polymyxa was 7.0. Both enzymes were activated by Cu++. The molecular weight of the first enzyme was 29,400 and that for the second enzyme was 18,000 on the...
Article
The L-asparaginase (E.C.3.5.1.1) produced by chicken liver was isolated and characterized. Different purification steps (including ammonium sulphate fractionation followed by separation on Sephadex G-100 gel filtration and Sephadex G-200 gel filtration) were applied to crude filtrate to obtain a pure enzyme preparation. The enzyme was purified 128....
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Three strains of Rhizopus oligosporus, the edible fun-gus used in making of tempeh food, were screened with re-spect to formation of inulinase activities, and R. oligosporus NRRL-2710 gave the highest levels of enzyme activity. Fur-ther studies of inulinase production by R. oligosporus have shown that the highest inulinase levels were obtained with...
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Four strains of Rhizopus oligosporus were screened for their abilities to produce glucoamylase enzyme on potato starch medium. R. oligosporus DSM 1964 produced the highest levels of extracellular glucoamylase activity. The optimization of the culture conditions was carried out. En-zyme productivity was enhanced on media supplemented with xylose 1%...
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Date seeds (Phoenix dactylifera) were selected from a screening programmed for lipid hydrolysis by lipase. Two lipase enzymes (L1 and L2) were isolated and purified from date seeds by simple extraction with distilled water and gel filtration on two successive columns filled with Sephadex G-100 and G-200. They were purified to final specific activ-i...
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A neutral protease of 64000 Dalton molecular weight, named raphanin, has been isolated in a homogeneous state from leaves of Raphanus sativus (Radish). The enzyme was purified by a sequence of fractional precipitation with ammonium sulfate, adsorption on hydroxylapatite chromatography, followed by gel filtration chromatography on two successive col...
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Romman peels, zaater leaves, garlic bulbs, helba seeds, habbit el baraka seeds, cabbage leaves and stems and red beet leaves, collected from Egypt, exhibit wide spectrum antimicrobial effects against Gram positive and Gram negative bacteria, yeast and fungi. The most antimicrobial bioactive dry plant powders were romman peels, cabbage stems, red be...
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Chitinase, laminarinase A and laminarinase B were extracted and purified from Egyptian sugar beet ( Beta vulgaris) leaves. Chitinase showed higher heat stability than laminarinase A and laminarinase B when heated at 50?C for 60 min. Chitinase activity was quite stable in water than in buffer, while laminarinase A and laminarinase B activities incre...
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Pichia pinus was found to be capable of growing on mango wastes, producing pectinase (pectin lyase, EC-4.2.2.10) and lactase (beta-galactosidase, EC-3.2.1.23) enzymes. The two enzymes were successively purified by precipitation with ammonium sulfate followed by chromatography on Sephadex G-120. The purification procedure provided 1,846 and 929 fold...
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The activity of enzyme hydrolyzing colloidal chitin has been measured on extracts from a number of higher plants belonging to eleven families. Chitinase activity could be detected in dry seeds which increased during germination. Its relationship to different vegetative plant tissues was investigated. Sugar beet leaves ( Beta vulgaris ) provided the...
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Cellulase and salicinase were purified from aqueous extract of fresh healthy Beta vulgaris leaves by ammonium sulfate fractionation and successive chromatography on DEAE-cellulose, Sephadex G120 and G200 columns with 33.2 and 30.4% recovery of their activities respectively. The molecular weights of pure cellulase and salicinase were estimated by ge...
Article
Laminarinase A and laminarinase B (β-1,3-glucanase, EC 3.2.1.6) were quantitatively measured in extracts from 37 of vegetative parts and seeds (dry and germinated) representing 24 plants of eleven families. Egyptian sugar beet leaves were found to be the most considerable producer of these enzymes in the screened plants. The optimum conditions for...
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The enzyme β-amylase (1,4-α-d-Glucan maltohydrolase, E.C. 3.2.1.2) was isolated and purified to homogenity from the extract of healthy radish roots (Raphanus sativus). The purification involved ammonium sulphate precipitation (100% saturation); DEAE-cellulose; hydroxylapatite and Sephadex G-200 chromatography. The purity and homogenity of the enzym...
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Glycosidases namely myrosinase and β-amylase, have been isolated fromBrassicaceae. These enzymes were identified and estimated by the rate of glucose and maltose formation from sinigrin (thioglucosinolate) and amylose (polysaccharides) hydrolysis, respectively. Their activities (U/g dry tissues) varied with the different species of the plant and wi...
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Two myrosinase isoenzymes ( EC 3. 2. 3. 1 ) were extracted and purified by (NH4)2SO4 precipitation and DEAE-cellulose and Sephadex G-200 chromatography from radish root tissues with Mrs 28 800 and 58 900. The most active one (120 U mg−1) was identified and characterized. The yield of the purified myrosinases was 21 mg (2398 U) of pure enzymes from...
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A number of glycosidase enzymes have been isolated and identified in healthy fresh leaves of turnip. Myrosinase (β-thioglucosidase, EC. 3.2.3.1), disaccharase (β-fructofuranosidase, EC. 3.2.1.26), andβ-amylase (α-1,4-glucan maltohydrolase, EC 3.2.1.2) have been isolated and purified in powder form. The purification methods were salting out with amm...
Article
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Four myrosinase (β-thioglucosidase EC. 3.2.3.1) and seven disaccharase (β-fructofuranosidase, EC. 3.2.1.26) isoenzymes were isolated from turnip leaves. The most active enzymes were isolated in pure form. Myrosinase and disaccharase mol wt was 62.0 × 103 and 69.5 × 103 dalton, respectively, on the basis of gel filtration on Sephadex G-200. Myrosina...
Article
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Properties of polygalacturonase [E.C. 3.2.1.15] (E1) and invertase (E.C. 3.2.1.26] (E2) isolated and purified in powdered form from Endomycopsis fibuligera grown on date wastes were measured. The molecular weights were estimated to be about 32000 and 69500, and they were highly specific for hydrolysing (1–4) and (1–2) glycosidic links respectively....
Article
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A number of glycosidase enzymes have been isolated and identified in healthy fresh leaves of turnip. Myrosinase (fi-thioglucosidase, EC. 3.2.3.1), disaccharase (fi-fructofuranosidase, EC. 3.2.1.26), and fi-amylase (o~-l,4-glucan maltohydrolase, EC 3.2.1.2) have been isolated and purified in powder form. The purification methods were salting out wit...
Article
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Proteolytic activity of a fibrinolytic enzyme isolated from B. subtilis was tested on fibrin plates plasminogen-free and plasminogen-rich. Results showed that the enzyme is not a plasminogen activator. Inhibitory effect of human serum and plasma was also tested. The plasma and not serum showed a slight inhibitory effect on proteolytic activity of t...
Article
Two fibrinolytic enzymes isolated from B. subtilis and from B. polymyxa were purified using a five step method. The pH optimum for the enzyme from B. subtilis was 7.2 and for the enzyme from B. polymyxa was 7.0. Both enzymes were activated by Cu++. The molecular weight of the first enzyme was 29,400 and that for the second enzyme was 18,000 on the...
Article
Full-text available
A fibrinolytic enzyme obtained from B. subtilis was purified, using DEAE-cellulose column chromatography, and gel filtration on Sephadex G-100. The preparation was homogeneous as tested by gel filtration on Sephadex G-200, and disc electrophoresis. The molecular weight of this enzyme was 29.400 estimated by gel filtration on Sephadex G-100. The opt...