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)

A strain of Bacillus pumilus produced an extracellular pectic enzyme with polygalacturonic acid as the substrate. This enzyme, with optimal activity at pH 8.0 to 8.5, produced reaction products that strongly absorbed light at 232 nm, indicating the presence of a pectic acid trans-eliminase (PATE). Neither pectin esterase nor polygalacturonase was detected in the cell-free culture fluid. Chromatographic examination of the end products revealed the presence of large quantities of unsaturated oligouronides unlike those found with B. polymyxa. It was found that the PATE was produced extracellularly during the negative logarithmic death phase of the organism. The filtrate from sonically treated cells did not show any activity for PATE or hydrolases for lower oligogalacturonides at any time during the growth cycle. The enzyme was inducible. Pectin, National Formulary (NF) was the best inducer, followed by polygalacturonic acid and galacturonic acid. Enzyme activity was markedly stimulated by calcium and other divalent ions. Copper and cobalt ions were inhibitory. The partially purified enzyme showed no significant activity on pectin containing a high methoxyl content (96% esterified). However, pectin NF with a lower methoxyl content (68% esterified) was attacked to a degree by the partially purified and crude enzyme preparations. The initial rate of PATE activity increased up to 60 C, about 16-fold higher than that observed at room temperature. The activation energy was calculated as 12,183 cal/mole. A protective action of calcium chloride against heat inactivation of the PATE was observed. Degradation of polygalacturonic acid by this enzyme produced several unsaturated oligouronides soon after its addition to the substrate. The major endproduct was thought to be different from that of other known PATE enzymes. Paper chromatographic studies and viscosity measurements disclosed the random cleaving nature of the enzyme an endo-PATE.
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PMID:Purification and properties of an polygalacturonic acid trans-eliminase produced by Bacillus pumilus. 512 2

For the first time, a polygalacturonase from the culture broth of Tetracoccosporium sp. was isolated and incubated at 30 degrees C in an orbital shaker at 160 rpm for 48 h. The enzyme was purified by ammonium sulfate precipitation and two-step ion-exchange chromatography and had an apparent molecular mass of 36 kDa, as shown by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Its optimum activity was at pH 4.3 and 40 degrees C, and the Km and Vmax values of this enzyme (for polygalacturonic acid) were 3.23 mg/mL and 0.15 micromol/min, respectively. Ag+, Co2+, EDTA, Tween-20, Tween-80, and Triton X-100 stimulated polygalacturonase activity whereas Al3+, Ba2+, Ca2+, Fe2+, Fe3+, Ni2+, Mg2+, Mn2+, and SDS inhibited it. In addition, iodoacetamide and iodoacetic acid did not inhibit enzyme activity at a concentration of 1 mM, indicating that cysteine residues are not part of the catalytic site of polygalacturonase. We studied the kinetic properties and thermal inactivation of polygalacturonase. This enzyme exhibited a t1/2 of 63 min at 60 degrees C and its specific activity, turnover number, and catalytic efficiency were 6.17 U/mg, 113.64 min-1, and 35.18 mL/(min.mg), respectively. The activation energy (DeltaE#) for heat inactivation was 5.341 kJ/mol, and the thermodynamic activation parameters DeltaG#, DeltaH#, and DeltaS# were also calculated, revealing a potential application for the industry.
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PMID:Purification, characterization, kinetic properties, and thermal behavior of extracellular polygalacturonase produced by filamentous fungus Tetracoccosporium sp. 1729 7

Pectobacterium carotovorum (formerly Erwinia carotovora ssp. carotovora) is a phytopathogenic bacterium that causes soft rot disease, characterized by water-soaked soft decay, resulting from the action of cell wall-degrading exoenzymes secreted by the pathogen. Virulence in soft rot bacteria is regulated by environmental factors, host and bacterial chemical signals, and a network of global and gene-specific bacterial regulators. We isolated a mini-Tn5 mutant of P. carotovorum that is reduced in the production of extracellular pectate lyase, protease, polygalacturonase and cellulase. The mutant is also decreased in virulence as it macerates less host tissues than its parent and is severely impaired in multiplication in planta. The inactivated gene responsible for the reduced virulent phenotype was identified as corA. CorA, a magnesium/nickel/cobalt membrane transporter, is the primary magnesium transporter for many bacteria. Compared with the parent, the CorA(-) mutant is cobalt resistant. The mutant phenotype was confirmed in parental strain P. carotovorum by marker exchange inactivation of corA. A functional corA(+) DNA from P. carotovorum restored exoenzyme production and pathogenicity to the mutants. The P. carotovorum corA(+) clone also restored motility and cobalt sensitivity to a CorA(-) mutant of Salmonella enterica. These data indicate that CorA is required for exoenzyme production and virulence in P. carotovorum.
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PMID:CorA, the magnesium/nickel/cobalt transporter, affects virulence and extracellular enzyme production in the soft rot pathogen Pectobacterium carotovorum. 2172 93