Anti-WAS (aa 289-293) polyclonal antibody

We investigated the inhibitory effect and binding mechanism of four selected compounds (ascorbic acid, L-cysteine, glutathione, and citric acid) on membrane-bound polyphenol oxidases (mPPO) using spectroscopic and molecular docking techniques. Kinetic analysis demonstrated that these inhibitors reversibly inhibited the mPPO activity. Fluorescence spectroscopy revealed that the intrinsic fluorescence intensity of mPPO was quenched by inhibitors with a single class of the inhibition site on mPPO. Amino acid residues His 180, His 201, His 366, Cys 184, Glu 328, and Asn 333 were the important binding sites in the active center. These sites were identified using molecular docking techniques. Our findings suggested that the inhibitors were allosterically bound to the active center of mPPO through hydrogen bonds and ion contacts. This study provides new insights into the active site residues responsible for catalyzing mPPO and provides applicable information about the design of mPPO inhibitors.

The aim of this study was to evaluate the effects of freeze drying and oven drying on appearance, chemical components and antioxidant activities of three cultivars of tomatoes. This study showed cultivar 18,131 would provide the highest phenolic contents and ABTS radical scavenging activity, and cultivar 1862 provide the highest lycopene content after oven drying. On the basis of appearance and contents of polyphenols, freeze drying showed better results. However, oven drying was found superior in decreasing degradation of lycopene. The effects of drying on the polyphenol contents varied depending on the cultivars. In addition, there is no significant difference of antioxidant activities between freeze dried and oven dried tomatoes. These results also demonstrated that freeze drying is superior in maintaining physical structure and phenolic contents of tomato slices. However, oven drying is a viable option for drying tomatoes considering both costing and contents of lycopene.