Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pseudooligosaccharide acarbose is a potent inhibitor of amylases, glucosidases, and cyclodextrin glycosyltransferase and is clinically used for the treatment of so-called type II or insulin-independent diabetes. The compound consists of an unsaturated aminocyclitol, a deoxyhexose, and a maltose. The unsaturated aminocyclitol moiety (also called valienamine) is primarily responsible for the inhibition of glucosidases. Due to its structural similarity to maltotetraose, we have investigated whether acarbose is recognized as a substrate by the maltose/maltodextrin system of Escherichia coli. Acarbose at millimolar concentrations specifically affected the growth of E. coli K-12 on maltose as the sole source of carbon and energy. Uptake of radiolabeled maltose was competitively inhibited by acarbose, with a Ki of 1.1 microM. Maltose-grown cells transported radiolabeled acarbose, indicating that the compound is recognized as a substrate. Studying the interaction of acarbose with purified maltoporin in black lipid membranes revealed that the kinetics of acarbose binding to LamB is asymmetric. The on-rate of acarbose is approximately 30 times lower when the molecule enters the pore from the extracellular side than when it enters from the periplasmic side. Acarbose could not be utilized as a carbon source since the compound alone was not a substrate of amylomaltase (MalQ) and was only poorly attacked by maltodextrin glucosidase (MalZ).
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PMID:Acarbose, a pseudooligosaccharide, is transported but not metabolized by the maltose-maltodextrin system of Escherichia coli. 1019 28

Intravenous immunoglobulin infusion induces acute renal failure via a mechanism of osmotic nephrosis. Most reported cases are related to the use of sucrose-based intravenous immunoglobulin. Maltose-based intravenous immunoglobulin is thought to be a safer alternative and have a lower risk of renal toxicity than sucrose-based preparations. Maltase, but not sucrase, is present in the brush border of proximal convoluted renal tubules, where the maltose is metabolised. We report a case of maltose-based intravenous immunoglobulin-induced acute renal failure in an elderly diabetic woman. In this case, the risk factors included advanced age, hypovolaemia, sepsis, diabetes mellitus, and the high infusion rate of the intravenous immunoglobulin. Maltase is readily inhibited by hyperglycaemia; therefore, poor glycaemic control may predispose patients to develop acute renal failure even with the better-tolerated maltose-based intravenous immunoglobulin.
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PMID:Acute renal failure related to intravenous immunoglobulin infusion in an elderly woman. 1568 16

Acarbose, a pseudomaltotetraose, is produced by strains of the genus Actinoplanes. The compound is an inhibitor of alpha-glucosidases and is used in the treatment of patients suffering from type II diabetes. The benefits of acarbose for the producer are not known; however, a role as carbophor has been proposed. Acarbose synthesis is induced in the presence of maltose and maltotriose. We have investigated the transport activities for these sugars in Actinoplanes sp. strain SN 223/29 grown on different carbon sources, including acarbose. Under the conditions used, Actinoplanes sp. utilized acarbose as sole source of carbon and energy, although growth ceased after 24 h, possibly due to the accumulation of a toxic degradation product in the cytosol. Maltose transport was observed in cells grown on each of the substrates tested except glucose. Maltose transport of acarbose-grown cells was inhibited by sucrose and trehalose and, to a lesser extent, by maltodextrins but not by acarbose. In contrast, in maltose/maltotriose-grown cells maltose uptake was inhibited by acarbose. Maltotriose uptake in these cells was less inhibited by maltose but was more sensitive to acarbose than in acarbose-grown cells. The Km and Vmax values of maltose uptake are in the range of those reported for binding protein-dependent sugar ATP-binding cassette (ABC) transport systems. A maltose-binding protein that does not bind acarbose was isolated from cells grown on either acarbose, glycerol or maltose. These results suggest that an acarbose-insensitive maltose/sucrose/trehalose transporter that also accepts maltodextrins operates in acarbose-grown cells while a maltodextrin transporter that accepts maltose/sucrose/trehalose and is moderately sensitive to acarbose is found in cells grown in maltose/maltotriose-containing media.
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PMID:Characterization of maltose and maltotriose transport in the acarbose-producing bacterium Actinoplanes sp. 1593 74