Purification and characterization of α-glucosidase complex from the intestine of the frog, Rana japonica

Takesue, Yoshiki; Takesuè, Sachiko

doi:10.1016/0167-4838(96)00063-5

Cited by 12 publications

(2 citation statements)

References 26 publications

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“…Maltase activity was determined according to a method described previously [ 49 ] with some modifications. In brief, 10 μL of the homogenate (diluted 1/4 with 50 mM sodium phosphate, pH 6.5) was mixed with 10 μL of 56 mM maltose in 50 mM sodium phosphate, pH 6.5 for 60 min at 25 °C.…”

Section: Methodsmentioning

confidence: 99%

Morphological, biochemical, transcriptional and epigenetic responses to fasting and refeeding in intestine of Xenopus laevis

et al. 2016

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BackgroundAmphibians are able to survive for several months without food. However, it is unclear what molecular mechanisms underlie their survival. To characterize the intestinal responses to fasting and refeeding, we investigated morphological, biochemical, transcriptional and epigenetic changes in the intestine from adult male Xenopus laevis.ResultsFrogs were fed for 22 days, fasted for 22 days, or fasted for 21 days and refed for 1 day. Fasting reduced, and refeeding recovered partially or fully, morphological parameters (wet weight of the intestine, circumference of the epithelial layer and number of troughs in a villus-trough unit), activities of digestive enzymes and plasma biochemical parameters (glucose, triglycerides, cholesterol and free fatty acids). Reverse transcription-quantitative polymerase chain reaction analysis revealed overall suppression of the transcript levels by fasting, with various recovery rates on refeeding. Chromatin immunoprecipitation assays on the selected genes whose transcript levels declined with fasting and recovered quickly with refeeding, showed several euchromatin marks in histone (acetylation and methylation) and RNA polymerase II modifications (phosphorylation) with fasting, and returned to the feeding levels by refeeding. The mRNA levels of these genes responded to fasting and refeeding to greater extents than did the pre-mRNA levels, suggesting the involvement of post-transcriptional regulation.ConclusionsOur results demonstrate that the X. laevis intestine may undergo overall metabolic suppression at least at the transcriptional level to save energy during fasting and quickly recovered to moderate nutritional deficiency by refeeding, and suggest that these dietary responses of the intestine are epigenetically and post-transcriptionally regulated.Electronic supplementary materialThe online version of this article (doi:10.1186/s13578-016-0067-9) contains supplementary material, which is available to authorized users.

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Section: Methodsmentioning

confidence: 99%

Morphological, biochemical, transcriptional and epigenetic responses to fasting and refeeding in intestine of Xenopus laevis

et al. 2016

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“…Regarding linkage specificity, some reports indicate that, in addition of trimming the a1,3-linked glucose from the physiological substrate Glc 3 Man 9 GlcNAc 2 , mammalian a-glucosidase II is also active on maltose (Burns and Touster 1982;Brada and Dubach 1984) and that the same enzyme from C. albicans also cleaves maltose and kojibiose though to a much lower extent than nigerose (Torre-Bouscoulet et al 2004). Thus, it seems that a certain degree of unspecificity exists among these enzymes, a character also observed in a-glucosidases from bacterial (Berthelot and Delmotte 1999) and mammalian (Takesue and Takesue 1996) origins. Further evidence of the type of a-glucosidase purified in this study was obtained by testing the effect of selective inhibitors of N-glycan trimming glycosidases.…”

Section: Resultsmentioning

confidence: 93%

Purification and partial biochemical characterization of a membrane-bound type II-like α-glucosidase from the yeast morphotype of Sporothrix schenckii

Torres-Rodríguez

Flores-Berrout

Villagómez-Castro

et al. 2011

Antonie van Leeuwenhoek

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The early steps of glycoprotein biosynthesis involve processing of the N-glycan core by endoplasmic reticulum α-glucosidases I and II which sequentially trim the outermost α1,2-linked and the two more internal α1,3-linked glucose units, respectively. We have demonstrated the presence of some components of the enzymic machinery required for glycoprotein synthesis in Sporothrix schenckii, the etiological agent of human and animal sporotrichosis. However, information on this process is still very limited. Here, a distribution analysis of α-glucosidase revealed that 38 and 50% of total enzyme activity were present in a soluble and in a mixed membrane fraction, respectively. From the latter, the enzyme was solubilized, purified to apparent homogeneity and biochemically characterized. Analysis of the enzyme by denaturing electrophoresis and size exclusion chromatography revealed molecular masses of 75.4 and 152.7 kDa, respectively, suggesting a homodimeric structure. Purified α-glucosidase cleaved the fluorogenic substrate 4-methylumbelliferyl-α-D: -glucopyranoside with high affinity as judged from K(m) and V(max) values of 0.3 μM and 250 nmol of MU/min/mg protein, respectively. Analysis of linkage specificity using a number of glucose α-disaccharides as substrates demonstrated a clear preference of the enzyme for nigerose, an α1,3-linked disaccharide, over other substrates such as kojibiose (α1,2), trehalose (α1,1) and isomaltose (α1,6). Use of selective inhibitors of processing α-glucosidases such as 1-deoxynojirimycin, castanospermine and australine provided further evidence of the possible type of α-glucosidase. Accordingly, 1-deoxynojirimycin, a more specific inhibitor of α-glucosidase II than I, was a stronger inhibitor of hydrolysis of 4-methylumbelliferyl-α-D: -glucopyranoside and nigerose than castanospermine, a preferential inhibitor of α-glucosidase I. Inhibition of hydrolysis of kojibiose and maltose by 1-deoxynojirimycin and castanoespermine was significantly lower than that of nigerose. Taken together, these properties are consistent with a type II-like α-glucosidase probably involved in N-glycan processing. To our knowledge, this is the first report of such an activity in a truly dimorphic fungus.

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Selected Phyto and Marine Bioactive Compounds: Alternatives for the Treatment of Type 2 Diabetes

Reyes

Dufourt

Ross

et al. 2018

Studies in Natural Products Chemistry

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Purification and characterization of α-glucosidase complex from the intestine of the frog, Rana japonica

Cited by 12 publications

References 26 publications

Morphological, biochemical, transcriptional and epigenetic responses to fasting and refeeding in intestine of Xenopus laevis

Morphological, biochemical, transcriptional and epigenetic responses to fasting and refeeding in intestine of Xenopus laevis

Purification and partial biochemical characterization of a membrane-bound type II-like α-glucosidase from the yeast morphotype of Sporothrix schenckii

Selected Phyto and Marine Bioactive Compounds: Alternatives for the Treatment of Type 2 Diabetes

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