Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.21 (beta-glucosidase)
 3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Natural intoxication of livestock by the ingestion of Ipomoea carnea (Convolvulaceae) sometimes occurs in tropical regions of the world. Polyhydroxylated alkaloids were isolated from the leaves, flowers, and seeds of the poisonous plant and characterized. Chromatographic separation of the leaf extract resulted in the isolation of swainsonine (1), 2-epi-lentiginosine (2), calystegines B(1) (3), B(2) (4), B(3) (5), and C(1) (6), and N-methyl-trans-4-hydroxy-l-proline (7). The contents of 1 in the fresh leaves and flowers were 0.0029 and 0.0028%, respectively, whereas the contents of 1, 3, and 4 in the seeds were approximately 10 times higher than those in the leaves and flowers. Alkaloids 3, 4, and 6 showed a potent inhibitory activity toward rat lysosomal beta-glucosidase, with IC(50) values of 2.1, 0.75, and 0.84 microM, respectively, and alkaloid 5 was a moderate inhibitor of alpha- and beta-mannosidases. Although alkaloid 1 is known as a powerful inhibitor of lysosomal alpha-mannosidase (IC(50) = 0.02 microM), alkaloid 2, which has been thought to be an intermediate in the biosynthesis of 1, was also a potent inhibitor of alpha-mannosidase with an IC(50) value of 4.6 microM.
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PMID:Alkaloidal components in the poisonous plant, Ipomoea carnea (Convolvulaceae). 1290 59

There is natural intoxication of livestock by the ingestion of Ipomoea carnea (Convolvulaceae) in Brazil and other parts of the world. The alkaloidal glycosidase inhibitors swainsonine, 2-epi-lentiginosine, and calystegines B(1), B(2), B(3), and C(1) have been identified as constituents of this plant. Swainsonine is a potent inhibitor of rat lysosomal alpha-mannosidase, with an IC(50) value of 0.02 microM, whereas calystegines B(1), B(2), and C(1) are potent inhibitors of rat lysosomal beta-glucosidase, with IC(50) values of 2.1, 0.75, and 0.84 microM, respectively. The action of swainsonine results in a lysosomal storage disorder that closely mimics alpha-mannosidosis in humans. To determine whether the toxicity of I. carnea to livestock is due to purely swainsonine or due to a combination of effects by swainsonine and calystegines, intracellular lysosomal glycosidase activities in normal human lymphoblasts grown with inhibitors in the medium were examined. Incubation of lymphoblasts with 0.1 microM swainsonine for 3 days resulted in approximately 60% reduction of alpha-mannosidase activity. On the other hand, calystegines B(2) and C(1) showed no inhibition of beta-glucosidase up to 1 mM; instead inclusion of calystegines B(2) and C(1) at 100 microM in the culture medium increased its activity by 1.5- and 1.6-fold, respectively. Calystegines B(2) and C(1) seem to act as chemical chaperones, enhancing correct folding of the enzyme and enabling smooth trafficking to the lysosome. The lysosomal beta-glucosidase inhibitory calystegines seem to have little risk of inducing intoxication of livestock.
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PMID:Alkaloids from the poisonous plant Ipomoea carnea: effects on intracellular lysosomal glycosidase activities in human lymphoblast cultures. 1466 22