Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.15 (pectinase)
 2,440 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The characteristic features of the pectins present in the walls of immature fibre cells of the hypocotyl of flax seedlings have been studied by a combination of three subtractive methods (treatment with boiling water, calcium chelator, and free endopolygalacturonase), three staining reactions (periodic acid-thiocarbohydrazide-silver, Ruthenium Red, and ferric hydroxylamine) and labelling with an endopolygalacturonase-gold probe. The primary wall and the periphery of the tricellular junctions were shown to contain pectic molecules made of blocks either with free acidic functions or methyl-esterified, these molecules being removed from the wall by splitting alpha (1-4) linkages. On the contrary, the pectic molecules in the core of the tricellular junctions were mainly with free acidic groups, but with an appreciable acetylesterification of their hydroxyl groups; and they were linked with one another chiefly by calcium bonds. This unexpected constitution of the core of the tricellular junctions may be considered to be an early marker of the cells destined to give rise to the fibre bundles of the mature plant.
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PMID:Polysaccharide distribution in the cellular junctions of immature fibre cells of flax seedlings. 751 66

We report a new colorimetric assay to quantify endo-polygalacturonase activity, which hydrolyzes polygalacturonic acid to produce smaller chains of galacturonate. Some of the reported polygalacturonase assays measure the activity by detecting the appearance of reducing ends such as the Somogyi-Nelson method. As a result of being general towards reducing groups, the Somogyi-Nelson method is not appropriate when studying polygalacturonase and polygalacturonase inhibitors in plant crude extracts, which often have a strong reducing power. Ruthenium Red is an inorganic dye that binds polygalacturonic acid and causes its precipitation. In the presence of polygalacturonase, polygalacturonic acid is hydrolyzed bringing about a corresponding gain in soluble Ruthenium Red. The described assay utilizes Ruthenium Red as the detection reagent which has been used previously in plate-based assays but not in liquid medium reactions. The new method measures the disappearance of the substrate polygalacturonic acid and is compared to the Somogyi-Nelson assay. The experimental results using lemon peel, a fern fronds and castor leaf crude extracts demonstrate that the new method provides a way to the quickly screening of polygalacturonase activity and polygalacturonase inhibitors in plant crude extracts containing high amounts of reducing power. On the other hand, the Ruthenium Red assay is not able to determine the activity of an exo-polygalacturonase as initial velocity and thus would allow the differentiation between endo- and exo-polygalacturonase activities.
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PMID:A colorimetric method to quantify endo-polygalacturonase activity. 2211 20