Haruta M, Murata M, Hiraide A, Kadokura H, Yamasaki M, Sakuta M, Shimizu S, Homma S
Department of Nutrition and Food Science, University of Tokyo, Japan.
Biosci Biotechnol Biochem. 1998 Feb;62(2):358-62. doi: 10.1271/bbb.62.358.
Two PCR-amplified genomic DNA fragments encoding apple (cv. Fuji) polyphenol oxidase (PPO) were cloned and sequenced. A comparison of genomic DNA with cDNAs revealed that the PPOs lacked introns. Both PPO DNAs appear to encode a 66-kDa precursor protein consisting of a 56-kDa mature protein and a N-terminal transit peptide of 10-kDa N-terminal transit peptide. Apple PPO DNA was expressed in Escherichia coli, and the gene product (56 kDa) without a transit peptide was immunochemically detected and was the same size (ca. 65 kDa) as the main PPO of apple fruit by SDS-PAGE.
克隆并测序了两个编码苹果（富士品种）多酚氧化酶（PPO）的PCR扩增基因组DNA片段。基因组DNA与cDNA的比较表明，PPO缺乏内含子。两个PPO DNA似乎都编码一个66 kDa的前体蛋白，该前体蛋白由一个56 kDa的成熟蛋白和一个10 kDa的N端转运肽组成。苹果PPO DNA在大肠杆菌中表达，通过SDS-PAGE免疫化学检测到没有转运肽的基因产物（56 kDa），其大小与苹果果实的主要PPO相同（约65 kDa）。
