TY  - JOUR
AU  - Polović, Natalija
AU  - Pjanović, Rada
AU  - Burazer, Lidija M.
AU  - Veličković, Sava
AU  - Jankov, Ratko
AU  - Ćirković-Veličković, Tanja
PY  - 2009
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1488
AB  - BACKGROUND: It is thought that food sensitisers must be able to reach the intestine in order to sensitise patients. Pectin is a gel-forming plant polysaccharide that can protect allergens from in vivo gastric digestion and in vitro pepsin digestion. The aim of this study was to examine if pectin gel formed in the acidic environment of the stomach can protect labile allergen from in vitro gastrointestinal digestion. RESULTS: Pectin forms a gel in the acidic conditions of gastric fluid up to a concentration of 1.0 +/- 0.14 g L(-1). Four allergenic fruits (kiwi, cherry, apple and banana) form gels in the same manner at the dilutions 14.8 +/- 0.4; 8.4 +/- 0.2, 9.4 +/- 0.35 and 29.1 +/- 0.2, respectively. The time necessary for dissolution of 50 g L(-1) pectin gel in intestinal fluid was found to be 70 +/- 0.2 min. Pectin gel formed in situ was able to protect Act c 1 from pepsin digestion for 1 h and from further intestinal digestion for one additional hour. CONCLUSION: Pectin gel in an acidic environment protects Act c 1 from pepsin digestion and dissolves slowly in the slightly basic environment of the intestine allowing the survival of fruit allergen for additional time and possible interaction with the gut immune system.
PB  - John Wiley & Sons Ltd, Chichester
T2  - Journal of the Science of Food and Agriculture
T1  - Acid-formed pectin gel delays major incomplete kiwi fruit allergen Act c 1 proteolysis in in vitro gastrointestinal digestion
EP  - 14
IS  - 1
SP  - 8
VL  - 89
DO  - 10.1002/jsfa.3404
ER  - 

@article{
author = "Polović, Natalija and Pjanović, Rada and Burazer, Lidija M. and Veličković, Sava and Jankov, Ratko and Ćirković-Veličković, Tanja",
year = "2009",
abstract = "BACKGROUND: It is thought that food sensitisers must be able to reach the intestine in order to sensitise patients. Pectin is a gel-forming plant polysaccharide that can protect allergens from in vivo gastric digestion and in vitro pepsin digestion. The aim of this study was to examine if pectin gel formed in the acidic environment of the stomach can protect labile allergen from in vitro gastrointestinal digestion. RESULTS: Pectin forms a gel in the acidic conditions of gastric fluid up to a concentration of 1.0 +/- 0.14 g L(-1). Four allergenic fruits (kiwi, cherry, apple and banana) form gels in the same manner at the dilutions 14.8 +/- 0.4; 8.4 +/- 0.2, 9.4 +/- 0.35 and 29.1 +/- 0.2, respectively. The time necessary for dissolution of 50 g L(-1) pectin gel in intestinal fluid was found to be 70 +/- 0.2 min. Pectin gel formed in situ was able to protect Act c 1 from pepsin digestion for 1 h and from further intestinal digestion for one additional hour. CONCLUSION: Pectin gel in an acidic environment protects Act c 1 from pepsin digestion and dissolves slowly in the slightly basic environment of the intestine allowing the survival of fruit allergen for additional time and possible interaction with the gut immune system.",
publisher = "John Wiley & Sons Ltd, Chichester",
journal = "Journal of the Science of Food and Agriculture",
title = "Acid-formed pectin gel delays major incomplete kiwi fruit allergen Act c 1 proteolysis in in vitro gastrointestinal digestion",
pages = "14-8",
number = "1",
volume = "89",
doi = "10.1002/jsfa.3404"
}

Polović, N., Pjanović, R., Burazer, L. M., Veličković, S., Jankov, R.,& Ćirković-Veličković, T.. (2009). Acid-formed pectin gel delays major incomplete kiwi fruit allergen Act c 1 proteolysis in in vitro gastrointestinal digestion. in Journal of the Science of Food and Agriculture
John Wiley & Sons Ltd, Chichester., 89(1), 8-14.
https://doi.org/10.1002/jsfa.3404

Polović N, Pjanović R, Burazer LM, Veličković S, Jankov R, Ćirković-Veličković T. Acid-formed pectin gel delays major incomplete kiwi fruit allergen Act c 1 proteolysis in in vitro gastrointestinal digestion. in Journal of the Science of Food and Agriculture. 2009;89(1):8-14.
doi:10.1002/jsfa.3404 .

Polović, Natalija, Pjanović, Rada, Burazer, Lidija M., Veličković, Sava, Jankov, Ratko, Ćirković-Veličković, Tanja, "Acid-formed pectin gel delays major incomplete kiwi fruit allergen Act c 1 proteolysis in in vitro gastrointestinal digestion" in Journal of the Science of Food and Agriculture, 89, no. 1 (2009):8-14,
https://doi.org/10.1002/jsfa.3404 . .

TY  - JOUR
AU  - Ahmed, Khaled S.O.H.
AU  - Milosavić, Nenad
AU  - Popović, Milica M.
AU  - Prodanović, Radivoje
AU  - Knežević, Zorica
AU  - Jankov, Ratko
PY  - 2007
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1111
AB  - α-Glucosidase from S. cerevisiae was covalently immobilized onto Sepabeads EC-EA by the glutaraldehyde method. An analysis of the variables controlling the immobilization process is first presented and it is shown that the highest coupling of α-glucosidase occurred within 24 h. Also, a loading of 30 mg/g support proved to be effective, resulting in a rather high activity of around 45 U g-1 with a satisfactory degree of enzyme fixed. Both free and immobilized enzymes were then characterized by determining the activity profile as a function of pH, temperature and thermal stability. The obtained immobilized preparation showed the same optimum pH, but a higher optimum temperature compared with the soluble one. In addition, the immobilized enzyme treated at 45 ºC for 1 h still retained an activity of around 20 %, whereas the free enzyme completely lost its original activity under this condition. In conclusion, the developed immobilization procedure is quite simple, easily reproducible and provides a promising solution for the application of immobilized α-glucosidase.
AB  - Maltaza iz S. cerevisiae je kovalentno imobilizovana na Sepabeads EC-EA nakon aktivacije nosača rastvorom glutaraldehida. Ispitivanjem kinetike imobilizacije utvrđeno je da se 25 % enzima imobilizuje nakon 24 časa. Imobilizovana α-glukozidaza ima isti pH optimum kao i rastvorni enzim, dok je optimalna temperatura za aktivnost imobilizovanog enzima uvećana za 10 °C u poređenju sa rastvornim enzimom. Kada se uporede zaostale aktivnosti rastvorne i imobilizovane forme α-glukozidaze, nakon inkubacije od 1 h na 45 °C rastvorni enzim ne pokazuje aktivnost dok imobilizovana forma zadržava oko 20 % početne aktivnosti. Imobilizovana forma enzima zadržava 20 % početne aktivnosti čak i posle 3 h inkubacije na 45 °C.
PB  - Serbian Chemical Society, Belgrade
T2  - Journal of the Serbian Chemical Society
T1  - Preparation and studies on immobilized α-glucosidase from baker’s yeast Saccharomyces cerevisiae
T1  - Dobijanje i proučavanje imobilizacije α-glukozidaze iz pekarskog kvasca Saccharomyces cerevisiae
EP  - 1263
IS  - 12
SP  - 1255
VL  - 72
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1111
ER  - 

@article{
author = "Ahmed, Khaled S.O.H. and Milosavić, Nenad and Popović, Milica M. and Prodanović, Radivoje and Knežević, Zorica and Jankov, Ratko",
year = "2007",
abstract = "α-Glucosidase from S. cerevisiae was covalently immobilized onto Sepabeads EC-EA by the glutaraldehyde method. An analysis of the variables controlling the immobilization process is first presented and it is shown that the highest coupling of α-glucosidase occurred within 24 h. Also, a loading of 30 mg/g support proved to be effective, resulting in a rather high activity of around 45 U g-1 with a satisfactory degree of enzyme fixed. Both free and immobilized enzymes were then characterized by determining the activity profile as a function of pH, temperature and thermal stability. The obtained immobilized preparation showed the same optimum pH, but a higher optimum temperature compared with the soluble one. In addition, the immobilized enzyme treated at 45 ºC for 1 h still retained an activity of around 20 %, whereas the free enzyme completely lost its original activity under this condition. In conclusion, the developed immobilization procedure is quite simple, easily reproducible and provides a promising solution for the application of immobilized α-glucosidase., Maltaza iz S. cerevisiae je kovalentno imobilizovana na Sepabeads EC-EA nakon aktivacije nosača rastvorom glutaraldehida. Ispitivanjem kinetike imobilizacije utvrđeno je da se 25 % enzima imobilizuje nakon 24 časa. Imobilizovana α-glukozidaza ima isti pH optimum kao i rastvorni enzim, dok je optimalna temperatura za aktivnost imobilizovanog enzima uvećana za 10 °C u poređenju sa rastvornim enzimom. Kada se uporede zaostale aktivnosti rastvorne i imobilizovane forme α-glukozidaze, nakon inkubacije od 1 h na 45 °C rastvorni enzim ne pokazuje aktivnost dok imobilizovana forma zadržava oko 20 % početne aktivnosti. Imobilizovana forma enzima zadržava 20 % početne aktivnosti čak i posle 3 h inkubacije na 45 °C.",
publisher = "Serbian Chemical Society, Belgrade",
journal = "Journal of the Serbian Chemical Society",
title = "Preparation and studies on immobilized α-glucosidase from baker’s yeast Saccharomyces cerevisiae, Dobijanje i proučavanje imobilizacije α-glukozidaze iz pekarskog kvasca Saccharomyces cerevisiae",
pages = "1263-1255",
number = "12",
volume = "72",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1111"
}

Ahmed, K. S.O.H., Milosavić, N., Popović, M. M., Prodanović, R., Knežević, Z.,& Jankov, R.. (2007). Preparation and studies on immobilized α-glucosidase from baker’s yeast Saccharomyces cerevisiae. in Journal of the Serbian Chemical Society
Serbian Chemical Society, Belgrade., 72(12), 1255-1263.
https://hdl.handle.net/21.15107/rcub_technorep_1111

Ahmed KS, Milosavić N, Popović MM, Prodanović R, Knežević Z, Jankov R. Preparation and studies on immobilized α-glucosidase from baker’s yeast Saccharomyces cerevisiae. in Journal of the Serbian Chemical Society. 2007;72(12):1255-1263.
https://hdl.handle.net/21.15107/rcub_technorep_1111 .

Ahmed, Khaled S.O.H., Milosavić, Nenad, Popović, Milica M., Prodanović, Radivoje, Knežević, Zorica, Jankov, Ratko, "Preparation and studies on immobilized α-glucosidase from baker’s yeast Saccharomyces cerevisiae" in Journal of the Serbian Chemical Society, 72, no. 12 (2007):1255-1263,
https://hdl.handle.net/21.15107/rcub_technorep_1111 .

TY  - JOUR
AU  - Knežević, Zorica
AU  - Milosavić, Nenad
AU  - Bezbradica, Dejan
AU  - Jakovljević, Živana
AU  - Prodanović, Radivoje
PY  - 2006
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/990
AB  - The present study compares the results of three different covalent immobilization methods employed for immobilization of lipase from Candida rugosa on Eupergit C supports with respect to enzyme loadings, activities and coupling yields. It seems that method yielding the highest activity retention of 43.3% is based on coupling lipase via its carbohydrate moiety previously modified by periodate oxidation. Study of thermal deactivation kinetics at three temperatures (37, 50 and 75 degrees C) revealed that the immobilization method also produces an appreciable stabilization of the biocatalyst, changing its thermal deactivation profile. By comparison of the t(1/2) values obtained at 75 C, it can be concluded that the lipase immobilized via carbohydrate moiety was almost 2-fold more stable than conventionally immobilized one and 18-fold than free lipase. The immobilization procedure developed is quite simple, and easily reproduced, and provides a promising solution for application of lipase in aqueous and microaqueous reaction system.
PB  - Elsevier, Amsterdam
T2  - Biochemical Engineering Journal
T1  - Immobilization of lipase from Candida rugosa on Eupergit (R) supports by covalent attachment
EP  - 278
IS  - 3
SP  - 269
VL  - 30
DO  - 10.1016/j.bej.2006.05.009
ER  - 

@article{
author = "Knežević, Zorica and Milosavić, Nenad and Bezbradica, Dejan and Jakovljević, Živana and Prodanović, Radivoje",
year = "2006",
abstract = "The present study compares the results of three different covalent immobilization methods employed for immobilization of lipase from Candida rugosa on Eupergit C supports with respect to enzyme loadings, activities and coupling yields. It seems that method yielding the highest activity retention of 43.3% is based on coupling lipase via its carbohydrate moiety previously modified by periodate oxidation. Study of thermal deactivation kinetics at three temperatures (37, 50 and 75 degrees C) revealed that the immobilization method also produces an appreciable stabilization of the biocatalyst, changing its thermal deactivation profile. By comparison of the t(1/2) values obtained at 75 C, it can be concluded that the lipase immobilized via carbohydrate moiety was almost 2-fold more stable than conventionally immobilized one and 18-fold than free lipase. The immobilization procedure developed is quite simple, and easily reproduced, and provides a promising solution for application of lipase in aqueous and microaqueous reaction system.",
publisher = "Elsevier, Amsterdam",
journal = "Biochemical Engineering Journal",
title = "Immobilization of lipase from Candida rugosa on Eupergit (R) supports by covalent attachment",
pages = "278-269",
number = "3",
volume = "30",
doi = "10.1016/j.bej.2006.05.009"
}

Knežević, Z., Milosavić, N., Bezbradica, D., Jakovljević, Ž.,& Prodanović, R.. (2006). Immobilization of lipase from Candida rugosa on Eupergit (R) supports by covalent attachment. in Biochemical Engineering Journal
Elsevier, Amsterdam., 30(3), 269-278.
https://doi.org/10.1016/j.bej.2006.05.009

Knežević Z, Milosavić N, Bezbradica D, Jakovljević Ž, Prodanović R. Immobilization of lipase from Candida rugosa on Eupergit (R) supports by covalent attachment. in Biochemical Engineering Journal. 2006;30(3):269-278.
doi:10.1016/j.bej.2006.05.009 .

Knežević, Zorica, Milosavić, Nenad, Bezbradica, Dejan, Jakovljević, Živana, Prodanović, Radivoje, "Immobilization of lipase from Candida rugosa on Eupergit (R) supports by covalent attachment" in Biochemical Engineering Journal, 30, no. 3 (2006):269-278,
https://doi.org/10.1016/j.bej.2006.05.009 . .