polyphenol oxidase (ppo) from tomatoes was extracted and partially purified through  (nh4)2so4 precipitation, dialysis and ion exchange chromatography. the activity of polyphenol oxidase was investigated in solanum lycopersicum. spectrophotometric method was used to assay the enzyme activity and the kinetic constants - maximum enzyme velocity (vmax) and michealis - menten constant (km). of the ...

The effects of heat shock on PPO and POD activity in minimally processed Iceberg lettuce was examined during storage (10 days). The results were compared with the effect of temperature on crude extracts of these enzymes (in vitro analysis). Fresh-cut lettuce washed at 50 degrees C showed significantly lower PPO and POD activity throughout storage than lettuce washed at 4 degrees C and 25 degree...

The biochemical anti-herbivore defense of trembling aspen (Populus tremuloides Michx.) was investigated in a molecular analysis of polyphenol oxidase (PPO; EC 1.10.3.2). A PPO cDNA was isolated from a trembling aspen wounded leaf cDNA library and its nucleotide sequence determined. Southern analysis indicated the presence of two PPO genes in the trembling aspen genome. Expression of PPO was fou...

The activities of polyphenol oxidase (PPO) and peroxidase (POD) in hot pepper (Capsicum annuum L.) pericarp were evaluated using spectrophotometric method. The enzymes were extracted from the pepper pericarp 5 g with 20 mL of 0.1 M phosphate buffer solution pH 7. PPO and POD activities were determined using catechol and guaiacol as a substrate, respectively. The effects of the amounts of enzyme...

Protoporphyrinogen IX oxidase (PPO), the last common enzyme of haem and chlorophyll biosynthesis, catalyses the oxidation of protoporphyrinogen IX to protoporphyrin IX. The membrane-embedded flavoprotein is the target of a large class of herbicides. In humans, a defect in PPO is responsible for the dominantly inherited disease variegate porphyria. Here we present the crystal structure of mitoch...

Increasing the polyunsaturated fatty acid (PUFA) composition of milk is acknowledged to be of benefit to consumer health. Despite the high PUFA content of forages, milk fat contains only about 3% of PUFA and only about 0.5% of n-3 fatty acids. This is mainly due to intensive lipid metabolism in the rumen (lipolysis and biohydrogenation) and during conservation (lipolysis and oxidation) such as ...

Purulent otorrhea is the most common complication of tympanostomy tube (TT) insertion. It may occur in the postoperative period or at any time during the sojourn of the tube. The efficacy of topical antimicrobial prophylaxis against purulent postoperative otorrhea (PPO) has been examined in 5 prospective, randomized studies; all demonstrated a reduction in PPO from topical antimicrobial prophyl...

BACKGROUND Inflammatory responses to wear debris cause osteolysis that leads to aseptic prosthesis loosening and hip arthroplasty failure. Although osteolysis is usually associated with aseptic loosening, it is rarely seen around stable implants. Aseptic implant loosening is a simple radiologic phenomenon, but a complex immunological process. Particulate debris produced by implants most commonl...

Paper presents predator–prey based optimization (PPO) technique to obtain optimal generation scheduling of short-term hydrothermal system. PPO is a part of the swarm intelligence family and is capable to solve large scale non-linear optimization problems. PPO based algorithm combines the idea of particle swarm optimization concept with predator effect that helps to, maintain diversity in the sw...

OBJECTIVE This study aims to compare the pelvic biomechanics of patients who underwent Salter innominate osteotomy (SIO) for one hip and Pemberton pericapsular osteotomy (PPO) for the other hip. MATERIALS AND METHODS Fifty-seven of 126 patients who received a one-stage procedure involving SIO for one hip and PPO for the other hip were included in this series. Preoperative x-rays, archived rep...