Polyphenol oxidase (PPO), a copper-containing metalloprotein, catalyzes the oxidation of phenolics to quinones which make brown pigments in wounded tissues. Because the phenomena decrease fruit quality, PPO has been regarded to be a critical enzyme in food technology. In the course of expressed sequence tags (ESTs) analysis of the Fuji apple (Malus domesticus Borkh.), we identified two partial ...

Arthropod phenoloxidase (PO) generates quinones and other toxic compounds to sequester and kill pathogens during innate immune responses. It is also involved in wound healing and other physiological processes. Insect PO is activated from its inactive precursor, prophenoloxidase (PPO), by specific proteolysis via a serine protease cascade. Here, we report the crystal structure of PPO from a lepi...

Tetralobulate glandular trichomes are present on the foliage of many solanaceous species. Resistance of many of these species to insects is conditioned by the ability of trichomes to rupture upon contact and to rapidly polymerize their contents, resulting in entrapment of insects in hardened trichome exudate. In the wild potato, Solanum berthaultii, polymerization of trichome exudate is initiat...

Precise modification by gene targeting (GT) provides an important tool for studies of gene function in vivo. Although routine with many organisms, only isolated examples of GT events have been reported for flowering plants. These were at low frequencies precluding reliable estimation of targeting efficiency and evaluation of GT mechanisms. Here we present an unambiguous and straightforward syst...

The protection of Cumalic acid (CA), antioxidant, in the biochemical process nature has aroused great interest. Polyphenol oxidase (PPO), an enzyme, plays a vital function aging and browning plants, such as vegetables, fruits, mushrooms. interaction CA PPO reveals important information metabolism aging. Thus, molecular mechanism binding with polyphenol (PPO) was explored by combining spectrosco...

the effect of ca, zn and b foliar application (five g l-1) and their mixed applications as well as two harvest dates (1st and 15st of august) on ppo activity of two commercial asian pears (‘ks’9 and ‘ks’13) fruits at the time of harvest and during storage were investigated. results showed that the ppo activity increased from harvest time to three months after storage and then decreased. during ...

Adaptation of polyphenol oxidase measuring methods (AACCI Method 22-85) for wheat meal and flour and their relationship to alkaline noodle color Noodle color is a critical sensory attribute in raw noodles. Darkening of noodles is due to the polyphenol oxidase (PPO) activity, which is a concern for the noodle industry and breeders. A method for measuring PPO activity of wheat kernels has been ap...

Advances in operative technique and perioperative care have considerably reduced surgical morbidity and mortality after pulmonary resections. Various single and combined parameters of functional operability have been proposed to assess the surgical risk. Pulmonary function tests adequately assess the pulmonary risk, and baseline or stress electrocardiography, echocardiography and nuclear cardia...

An accredited graduate orthodontic program provides advanced specialty education to meet standards of care mandated by the ADA, including both didactic and clinical components with defined outcome measures. To quantify these measures, the quality of care provided by graduate orthodontic students was compared to that of orthodontists in private practice. The quality of care was studied in two di...

A crude enzyme extract from Dioscorea esculenta var. fasiculata tissue subjected to ion exchange chromatography on DEAE-Sephadex A-50 column. This procedure resolved the extract into two main protein peaks one of which eluted through the column relatively unbound while the other protein peak which remained bound to the column was eluted with 1.0 M NaCl. Both protein peaks contained polyphenol o...