Production and characterization of homologous protoporphyrinogen IX oxidase (PPO) proteins: Evidence that small N-terminal amino acid changes do not impact protein function.

ABSTRACT: Transgenic soybean, cotton, and maize tolerant to protoporphyrinogen IX oxidase (PPO)-inhibiting herbicides have been developed by introduction of a bacterial-derived PPO targeted into the chloroplast. PPO is a membrane-associated protein with an intrinsic tendency for aggregation, making expression, purification, and formulation at high concentrations difficult. In this study, transgenic PPO expressed in three crops was demonstrated to exhibit up to a 13 amino acid sequence difference in the N-terminus due to differential processing of the chloroplast transit peptide (CTP). Five PPO protein variants were produced in and purified from E. coli, each displaying equivalent immunoreactivity and functional activity, with values ranging from 193 to 266 nmol min-1 mg-1. Inclusion of an N-terminal

SUBMITTER: Wang C 

PROVIDER: S-EPMC11426539 | biostudies-literature | 2024

REPOSITORIES: biostudies-literature