Heterologous expression of L-lysine {alpha}-oxidase from Scomber japonicus in Pichia pastoris and functional characterization of the recombinant enzyme

In this study, a synthetic gene coding for Scomber japonicus l-lysine α-oxidase, originally termed AIP (for apoptosis-inducing protein), was expressed in Pichia pastoris, and the recombinant enzyme (rAIP) was purified and characterized. rAIP exhibited essentially the same substrate specificity as the native enzyme, catalyzing the oxidative deamination of l-lysine as an exclusive substrate. rAIP was N-glycosylated and remained active over a wide range of pH, with an optimal pH of 7.5. The enzyme was stable in the pH range from 4.5 to 10.0 and was thermally stable up to 60°C. A molecular modelling of rAIP and a comparative structure/sequence analysis with homologous enzymes indicate that Asp220 and Asp320 are the substrate-binding residues that are likely to confer exclusive substrate specificity for l-lysine on the fish enzymes.

Source: Journal of Biochemistry - March 27, 2015 Category: Biochemistry Authors: Tani, Y., Omatsu, K., Saito, S., Miyake, R., Kawabata, H., Ueda, M., Mihara, H. Tags: Regular Papers Source Type: research