Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Homogenates of Giardia lamblia trophozoites exhibited the following hydrolase activities: acid phosphatase (EC 3.1.3.2), proteinase (EC 3.1.4) with urea-denatured hemoglobin and N-benzoyl-DL-arginine-2-naphthylamide as substrates, deoxyribonuclease (EC 3.1.4.5), and ribonuclease (EC 2.7.7.16). beta-N-Acetylglucosaminidase (EC 3.2.1.30), beta-galactosidase (EC 3.2.1.23), beta-glucuronidase (EC 3.2.1.31), alpha-D-glucosidase (EC 3.2.1.20), beta-D-glucosidase (EC 3.2.1.21), and beta-D-xylosidase (EC 3.2.1.37) activities were below the level of detection. Differential and isopycnic centrifugation of homogenates demonstrated that giardial hydrolases were localized in a single-particle population sedimenting at 7200g for 30 min. The particles had a buoyant density in sucrose of 1.15 and exhibited latency. Latency was completely destroyed by Triton X-100 or 15 cycles of freezing and thawing. After centrifugation of Triton- or freeze-thaw-treated particle fractions, the hydrolase activities, though no longer latent, were still sedimentable suggesting tight binding to the organelle membrane. Latency was destroyed simultaneously for all hydrolases, in direct proportion to the amount of Triton added to a particle preparation or to the number of times a particle preparation was subjected to freezing and thawing. These results support the suggestion that the hydrolases of G. lamblia trophozoites are localized in a single-particle population of lysosome-like organelles.
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PMID:Giardia lamblia: localization of hydrolase activities in lysosome-like organelles of trophozoites. 327 50

Axenic Tetrahymena pyriformis, syngen 1, mating type II cells were grown in Cox's defined medium. When washed and transferred into nonnutrient dilute salt solution or resuspended in the defined medium, the intact cells secrete acid hydrolases into the medium. Cells starving in the salt solution release in 5 hr about two-thirds of their beta-glucosidase, beta-N-acetylglucosaminidase, alpha-glucosidase, and amylase activities, about one-third of their deoxyribonuclease and phosphatase activities, smaller amounts of ribonuclease, and only a negligible fraction of their proteinase activity and protein content. During this period there is practically no change in the enzyme activities (except for a sudden increase of ribonuclease activity) and protein content of cells and medium together. Cells resuspended in the nutrient medium secrete enzymes as do the starved cells, but replace this loss, so that there is a continuous increase of the activities in the total system. According to isopycnic centrifugation experiments performed in sucrose gradients, the source of the hydrolases is a special population of lysosomes which disappear from the cells during starvation. This population equilibrates in the high density region of the gradients and contains the various acid hydrolases in about the proportion in which these enzymes appear in the medium.
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PMID:Secretion of acid hydrolases and its intracellular source in Tetrahymena pyriformis. 433 53