Phenylalanine, Tyrosine, and DOPA Are bona fide Substrates for Bambusa oldhamii BoPAL4

Phenylalanine ammonia-lyase (PAL) links the plant primary and secondary metabolisms, its product, trans-cinnamic acid, is derived into thousands of diverse phenylpropanoids. Bambusa oldhamii BoPAL4 has broad substrate specificity using L-phenylalanine, L-tyrosine, L-3,4-dihydroxy phenylalanine (L-DOPA) as substrates to yield p-coumaric caffeic respectively. The optimum reaction pH for three was measured at 9.0, 8.5, temperatures were obtained 50, 60, 40 °C, Km values 2084, 98, 956 μM, kcat 1.44, 0.18, 0.06 σ−1, major site mutant, BoPAL4-H123F, showed better affinity toward L-phenylalanine by decreasing value 640 μM increasing 1.87 s−1. In comparison wild-type BoPAL4, specific activities BoPAL4-H123F L-tyrosine L-DOPA retained 5.4% 17.8% residual activities. Therefore, are bona fide BoPAL4.