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A novel alpha-glucosidase from the moss Scopelophila cataractae

100%

Yamasaki Y., Nakashima S., Konno H.

Acta Biochimica Polonica

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2007

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tom 54

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nr 2

Scopelophila cataractae is a rare moss that grows on copper-containing soils. S. cataractae protonema was grown on basal MS medium containing copper. A starch-degrading activity was detected in homogenates of the protonema, after successive extraction with phosphate buffer and buffer containing 3 M LiCl. Buffer-soluble extract (BS) and LiCl-soluble extract (LS) readily hydrolyzed amylopectin to liberate only glucose, which shows that α-glucosidase (EC 3.2.1.20) in BS and LS hydrolyzed amylopectin. The Km value of BS for maltose was 0.427. The Km value of BS for malto-oligosaccharide decreased with an increase in the molecular mass of the substrate. The value for maltohexaose was 0.106, which is about four-fold lower than that for maltose. BS was divided into two fractions of α-glucosidase (BS-1 and BS-2) by isoelectric focusing. The isoelectric points of these two enzymes were determined to be 4.36 (BS-1) and 5.25 (BS-2) by analytical gel electrofocusing. The two enzymes readily hydrolyzed malto-oligosaccharides. The two enzymes also hydrolyzed amylose, amylopectin and soluble starch at a rate similar to that with maltose. The two enzymes readily hydrolyzed panose to liberate glucose and maltose (1 : 1), and the Km value of BS for panose was similar to that for maltotriose, whereas the enzymes hydrolyzed isomaltose only weakly. With regard to substrate specificity, the two enzymes in BS are novel α-glucosidases. The two enzymes also hydrolyzed β-limit dextrin, which has many α-1,6-glucosidic linkages near the non-reducing ends, more strongly than maltose, which shows that they do not need a debranching enzyme for starch digestion. The starch-degrading activity of BS was not inhibited by p-chloromercuribenzoic acid or α-amylase inhibitor. When amylopectin was treated with BS and LS in phosphate buffer, pH 6.0, glucose, but not glucose-1-phosphate, was detected, showing that the extracts did not contain phosphorylase but did contain an α-glucosidase. These results show that α-glucosidases should be capable of complete starch digestion by themselves in cells of S. cataractae.

2

Invertase and alpha-glucosidase production by the endemic Antarctic marine yeast Leucosporidium antarcticum

84%

Turkiewicz M., Pazgier M., Donachie S. P., Kalinowska H.

Polish Polar Research

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2005

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tom 26

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nr 2

125-136

The marine psychrophilic and endemic Antarctic yeast Leucosporidium antarcticum strain 171 synthesizes intracellular ß-fructofuranosidase, and intra- and extracellular α-glucosidases. Each enzyme is maximally produced at 5°C, while the strain's optimum growth temperature is 15°C. Invertase biosynthesis appeared regulated by catabolic repression, and induced by sucrose; the enzyme was extremely unstable ex vivo, and only EDTA, Mn2+, and BSA stabilized it for up to 12 h after yeast cell lysis. Thermal stability of the invertase was also low (30 min at temperatures up to 12°C). The optimum temperature for invertase activity was 30°C, and optimum pH was 4.55 to 4.75. The extracellular α-glucosidase was maximally active at 35°C and pH 6.70-7.50, and stable for 30 min up to 20°C.

3

Biochemical characterisation of alpha-glucosidase and beta-glucosidase in the alimentary canal of larval Leptinotarsa decemlineata Say, 1824 (Coleoptera: Chrysomelidae)

84%

Kazzazi M., Dehghanikhah F., Madadi H., Hosseininaveh V.

Polish Journal of Entomology

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2014

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tom 83

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nr 4

4

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Microbial enzymatic activity and its relation to organic matter abundance on sheltered and exposed beaches on the Polish coast

84%

Astel A. M., Bigus K., Stec M.

Oceanologia

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2018

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tom 60

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nr 3

5

In vitro alpha-glucosidase and alpha-amylase enzyme inhibitory effects of Andrographis paniculata extract and andrographolide

84%

Subramanian R., Asmawi M. Z., Sadikun A.

Acta Biochimica Polonica

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2008

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tom 55

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nr 2

391-398

There has been an enormous interest in the development of alternative medicines for type 2 diabetes, specifically screening for phytochemicals with the ability to delay or prevent glucose absorption. The goal of the present study was to provide in vitroevidence for potential inhibition of α-glucosidase and α-amylase enzymes, followed by a confirmatory in vivostudy on rats to generate a stronger biochemical rationale for further studies on the ethanolic extract of Andrographis paniculata and andrographolide. The extract showed appreciable α-glucosidase inhibitory effect in a concentration-dependent manner (IC50=17.2±0.15 mg/ml) and a weak α-amylase inhibitory activity (IC50=50.9±0.17 mg/ml). Andrographolide demonstrated a similar (IC50=11.0±0.28 mg/ml) α-glucosidase and α-amylase inhibitory activity (IC50=11.3±0.29 mg/ml). The positive in vitroenzyme inhibition tests paved way for confirmatory in vivostudies. The in vivostudies demonstrated that A. Paniculata extract significantly (P<0.05) reduced peak blood glucose and area under curve in diabetic rats when challenged with oral administration of starch and sucrose. Further, andrographolide also caused a significant (P<0.05) reduction in peak blood glucose and area under the curve in diabetic rats. Hence α-glucosidase inhibition may possibly be one of the mechanisms for the A. paniculataextract to exert antidiabetic activity and indicates that AP extract can be considered as a potential candidate for the management of type 2 diabetes mellitus.

6

Beta-glucan enzymatic hydrolysis in cereal grains and cereal products

84%

Michniewicz J., Kolodziejczyk P., Obuchowski W.

Electronic Journal of Polish Agricultural Universities. Series Food Science and Technology

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2003

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tom 06

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nr 1

The effect of various conditions of enzymatic hydrolysis as well as selected glucanolytic and amylolytic enzymes on carbohydrate system changes, necessary for quantitative determination of beta-glucan was evaluated. Hydrolysis of beta-glucan should be followed by elimination of starch in the sample using alpha-amylase Termamyl 120L and alpha-amyloglucosidase enzymes.

7

Activity of glycogen depolymerizing enzymes in extracts from brain tumor tissue [anaplastic astrocytoma and glioblastoma multiforme]

84%

Kotonski B., Wilczek J., Madej J., Zarzycki A., Hutny J.

Acta Biochimica Polonica

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2001

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tom 48

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nr 4

An approximately threefold increase in glycogenolytic activity of the neutral a-1,4-glucosidase and a twofold increase in the same activity of the acid isoform have been found in extracts of anaplastic astrocytoma and glioblastoma multiforme tumors of brain tissue. "Maltase activity" of the respective enzymes increased by 60-80% in both kinds of tumor extracts. However a significant decrease in a-amylase and almost complete disappearance of phosphorylase activities have also been found in both kinds of tumors.

Ograniczanie wyników

A novel alpha-glucosidase from the moss Scopelophila cataractae

Invertase and alpha-glucosidase production by the endemic Antarctic marine yeast Leucosporidium antarcticum

Biochemical characterisation of alpha-glucosidase and beta-glucosidase in the alimentary canal of larval Leptinotarsa decemlineata Say, 1824 (Coleoptera: Chrysomelidae)

Microbial enzymatic activity and its relation to organic matter abundance on sheltered and exposed beaches on the Polish coast

In vitro alpha-glucosidase and alpha-amylase enzyme inhibitory effects of Andrographis paniculata extract and andrographolide

Beta-glucan enzymatic hydrolysis in cereal grains and cereal products

Activity of glycogen depolymerizing enzymes in extracts from brain tumor tissue [anaplastic astrocytoma and glioblastoma multiforme]