แดง::: Assam for Polyphenoloriderse ACTivity. Polyphenoloxidase activity in HLS was measured spectrophotomctrically using L-DOPA as its substratc loxi oup) following the method of Adachi et al. (17) with a slight modification as mM previously described, except that an appropriate amount of a 50 mM HEPES buffer(pH 7.8) containing 5 mM MgCl2 and 5 mM CaCl2 was mL. mL. replaced by a L-ERT solution and p-amidinophenyl methanesulfonyl ance fluoride hydrochloride(p-APMSF). A 50 L aliquot of HLS was used in the assay system. The final concentration of the inhibitor added to the ng a action system was l mM
แดงๆ. Assay of peptidase activity was conducted using peptidyl-MCA as the substrate according to Morita et al. 120) as oxy achi cited by Adachi et al. (17) with some modifications. A 150 L portion of mph thc HLS was mixcd with 2235 AL of 50 mM HEPES(pH 7.8) containing 5 mM MgCI2 and 5 mM CaCl, and then the mixture was preincubated at of The room temperature for 10 min A 15 HL of 10 mM synthetic was added to initiate the reaction and it was terminated after 30 minincubation at 37 °C by adding 600HL of 50% acetic acid. An appropriate amount of the HEPES buffer was replaced by the solutions of LERT and p-APMSF The final concentration of the inhibitor added to the reaction system up) was 1 mM. Fluorescent assays wcrcdctcrmincd at 380 nm and 460 nm, using a Shimadzu model RF-1500 fluorescence spectrophoto- meter. The amount of the substrate hydrolyzed was calculated from the nga, value of 7-amino-4-methylcoumann(AMC standard solutions. Tocheck whether equal volumes of proteins were loaded in all samples, protein concentrations of the HLS were determined by the dye-binding method Bradford, using a Bio-Rad protein assay kit. For a calibration curve. con bovine serum albumin was used as a protein standard. l-a RT-PCR Analysis. Gene expressions of proPO from HLS treated with NAV and the control were quantified following the same protocol of the RT-PCR analysis as previously described. The final and concentration of the inhibitor added to the reaction system was l mM
แดงๆๆ:: Statissical Analyses. Microsoft Excel 2007 was used to calculate the PO means and standard deviation for all multiple measurements as well as for to generate graphs. Significant differences between the mean values were determined by one-way ANOVA. The level of significance setting nd a 0.05