Cloning and Expression of Phenylalanine Ammonia Lyase cDNA in Escherichia coli
苯丙氨酸脱氨酶cDNA在大肠杆菌中的克隆与表达

The phenylalanine ammonia lyase (PAL) cDNA was amplified from Petroselinum crispum total RNA by using RT PCR technique.The amplified 2.2kb DNA fragment was inserted into expression vecter pET23b.The resulting plasmid pET23bPAL was sequenced and then transformed into E.coli JM109DE3.The expressed PAL protein in JM109DE3(pET23bPAL)accounted for more than 15% of the total proteins in the recombinent E.coli cell.The activity and specificity of the expressed PAL was identified and tested by using HPLC technique,and showed good enough for application to enzymatic therapy of PKU.