Wyniki wyszukiwania - Biblioteka Nauki

1

The skeletal and heart muscle triacylglycerol lipolysis revisited

100%

Knapp M. , Gorski J.

Journal of Physiology and Pharmacology

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2017

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tom 68

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nr 1

2

Phospholipase D activity during long-term storage of Acer platanoides seeds in the imbibed state and desiccation of Acer saccharinum seeds

100%

Pukacka S.

Acta Physiologiae Plantarum

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1993

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tom 15

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nr 3

3

Purification and biochemical characteristic of a cold-active recombinant esterase from Pseudoalteromonas sp. 643A under denaturing conditions

80%

Dlugolecka A. , Cieslinski H. , Bruzdziak P. , Gottfried K. , Turkiewicz M. , Kur J.

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nr 3

211-218

EN

In this paper production of a cold-active esterase EstA from the Antarctic bacterium Pseudoalteromonas sp. 643A in E. coli expression system was described. The purification and biochemical characteristic of EstA were performed in the presence of urea and then compared with results obtained for the esterase with no addition of urea and isolated from the native source. In both cases the cold-active enzyme displayed similar properties. However, the differences concerning thermal activity were observed. The optimal temperature for recombinant esterase in the presence of urea (1 M) was about 15°C lower in comparison with enzyme isolated from the native source. Furthermore, the EstA was found to be more thermolabile in denaturant conditions. The differences were presumably caused by slightly changed protein structure in the presence of urea. The preservation of activity of EstA dissolved in buffer containing 8M urea suggests that the protein structure is retained and it does not undergo dramatic changes due to high urea concentration. This thesis was confirmed with FT-IR data.

4

Identification and molecular modeling of a novel lipase from an Antarctic soil metagenomic library

80%

Cieslinski H. , Bialkowska A. , Tkaczuk K. , Dlugolecka A. , Kur J. , Turkiewicz M.

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nr 3

199-204

EN

In this work, we present the construction of a metagenomic library in Escherichia coli using pUC19 vector and environmental DNA directly isolated from Antarctic topsoil and screened for lipolytic enzymes. Screening on agar supplemented with olive oil and rhodamine B revealed one clone with lipolytic activity (Lip 1) out of 11000 E. coli clones. This clone harbored a plasmid, pLip 1, which has an insert of 4722 bp that was completely sequenced from both directions. Further analysis of the insert showed three open reading frames (ORFs). ORF2 encoded a protein (Lip 1) of 469 amino acids with 93% identity to the uncultured Pseudomonas sp. lipase LipJ03. Amino acid sequence comparison and phylogenetic analysis indicated that Lip 1 lipase was closely related to family I subfamily 3. Furthermore, we present a three-dimensional model of lipase Lip 1 which was generated based on the two known structures of mesophilic lipases from Pseudomonas sp. MIS 38 (PML lipase, PDB; 2Z8X) and Seiratia marcescens (SML lipase, PDB: 2QUB). Finally, we report the results of comparisons between lipase Lip 1 and mesophilic lipases and point out similarities and differences in the catalytic site and in other parts of the analyzed structures.

5

Produkcja pozakomórkowych hydrolaz przez szczepy Yarrowia lipolytica pochodzące z sera

80%

Szoltysik M. , Chrzanowska J. , Zelazko M. , Niedbalska J. , Polomska X. , Juszczyk P. , Wojtatowicz M.

Acta Scientiarum Polonorum. Biotechnologia

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2008

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tom 07

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nr 4

6

Role of lipolytic and proteolytic enzymes in the pathogenesis of acute and chronic pancreatitis: an old story seen under nwe light

80%

Mossner J. , Wessig C. , Ogami Y. , Keim V.

Journal of Physiology and Pharmacology. Supplement

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1998

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tom 49

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nr 2

7

Drozdze piekarskie jako biokatalizator reacji hydrolizy estrow

70%

Majewska E. , Bialecka-Florjanczyk E. , Sulowska K.

Żywność Nauka Technologia Jakość. Suplement

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2006

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tom 13

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nr 2

190-197

PL

Jedną z metod modyfikacji tłuszczów jest reakcja enzymatycznego przeestryfikowania, wykorzystująca enzymy lipolityczne. Z uwagi na złożony proces izolacji enzymy te są reagentami kosztownymi i trudnodostępnymi. Alternatywnym rozwiązaniem może być użycie mikroorganizmów produkujących enzymy, bez konieczności wydzielania ich w czystej postaci. Rolę tę mogą spełniać drożdże piekarskie (Saccharomyces cerevisiae), które są źródłem różnych enzymów, wykazujących katalityczny wpływ na przebieg wielu reakcji chemicznych. Celem pracy było wstępne rozpoznanie możliwości wykorzystania drożdży piekarskich do modyfikacji triacylogliceroli. Jako modelową reakcję wybrano hydrolizę dioctanu heksano-1,2-diolu - estru zawierającego grupy acetylowe o różnej rzędowości. Proces hydrolizy prowadzono w obecności drożdży liofilizowanych, drożdży prasowanych lub biomasy szczepu Saccharomyces cerevisiae 102, jako biokatalizatorów, w roztworze wodnym, w temp. 30°C przy stałym mieszaniu. Postęp reakcji kontrolowano metodą chromatografii gazowej. Stwierdzono, że hydrolazy wydzielane przez drożdże wykazywały regioselektywność w stosunku do grup acetylowych o różnej rzędowości, powodując dwukrotnie szybszą hydrolizę grupy pierwszorzędowej, co stwarza praktyczne perspektywy wykorzystania drożdży piekarskich w przemianach acylogliceroli. Rodzaj użytych drożdży piekarskich nie miał znaczącego wpływu na szybkość reakcji.

EN

One of the methods of fats modifications is enzymatic interesterification, which uses lipolitic enzymes. Taking their complex isolation process into account, these enzymes are quite expensive and difficult to obtain. The employment of microorganisms, which release enzymes, may be the alternative solution to this problem, for example baker's yeast (Saccharomyces cerevisiae) could be possibly used. Baker's yeast are a great source of various enzymes, which may catalyze many chemical reactions. The objective of this study was to carry out initial investigations, aiming at employing baker's yeast in triacylglicerols modifications. As a model reaction a hydrolysis of hexane-1,2-diol diacetate (an ester containing esters groups of different order) was chosen. The experiments were carried out in the presence of liofilized and fresh baker's yeast as well as the breeding strain. The progress of the reactions was monitored by gas chromatography. It was proved that hydrolases released by baker's yeast showed positional specificity towards acetyl groups of different order - hydrolysis of primary group proceeded twice as fast. It may create practical opportunities for utilizing baker's yeast in triacylglicerols modifications. The variety of used yeast had not influenced on the speed of reaction.