Two polygalacturonases (PG I and PG II) have been separated from extracts of ripe peaches (Prunus persica) by chromatography on Sephadex G-100. PG I hydrolyzes polygalacturonic acid from the nonreducing ends of the molecules, releasing galacturonic acid as the product. It functions optimally at pH 5.5, requires Ca(2+) for activity, and hydrolyzes low molecular weight substrates most rapidly. In...

Extracted tomato polygalacturonase was purified by cation-exchange chromatography (and gel filtration) and characterized for molar mass, isoelectric point, as well as optimal pH for polygalacturonase activity. The enzymatic reaction of purified tomato polygalacturonase on polygalacturonic acid as substrate was investigated during a combined high-pressure/temperature treatment in a temperature r...

BACKGROUND To understand the intrinsic role of hydrolytic enzymes in sludge treatment, particularly their effect on the digestibility and dewaterability of sludge, activated sludge flocs were disintegrated using various techniques that included different enzymes (amylase, cellulase, proteinase, DNase, and polygalacturonase), pH adjustment, and temperature adjustment. The effectiveness of each e...

Yeast polygalacturonase (YPG) is a constitutive type enzyme, produced exocellularly and free of pectinesterase by Saccharomyces jragilis (1). It has an optimal pH of 4.4 and appears to be specific in its activity towards polygalacturonides (2). YPG differs from preparations of commercial fungus polygalacturonase in that it cannot carry out a complete breakdown of pectic acid to galacturonic aci...

The present study was undertaken to evaluate the characteristics of pectin methylesterase produced from Aspergillus niger. enzyme had a molecular weight 59.668 kDa. exhibited maximum activity at 45°C. lost most its initial after 20 min incubation 75°C. Optimal and stability occurred pH 4, with more than 90 % retained 10 5. Michaelis constant (Km) found equal (1) mg/ml, whereas, velocity (Vmax) ...

Although phospholipase C hydrolysis of polyphosphoinositides constitutes one of the major second messenger pathways in animal cells, its participation in signal transduction in higher plants has not been established. To determine whether activation of phosphatidylinositol-directed phospholipase C might be involved in signaling the elicitor-induced oxidative burst in plants, suspension-cultured ...

Bacteriophage phi29 is a small, well-characterized dsDNA virus that infects Bacillus subtilis. The anti-receptor of phi29 consists of oligomers of the 854-residue protein gp12 and plays an essential role in infection initiation by binding to the receptor on the host cell surface. Oligomers of gp12 exhibit a narrow spindle-shaped configuration 15 nm in length as revealed by electron microscopy a...