The Biocatalytic Potential of Aromatic Ammonia-Lyase from Loktanella atrilutea

Chembiochem. 2024 Feb 28:e202400011. doi: 10.1002/cbic.202400011. Online ahead of print.ABSTRACTCharacterization of the aromatic ammonia-lyase from Loktanella atrilutea (LaAAL) revealed reduced activity towards canonical AAL substrates: L-Phe, L-Tyr, and L-His, contrasted by its pronounced efficiency towards 3,4-dimethoxy-L-phenylalanine. Assessing optimal conditions, LaAAL exhibited maximal activity at pH 9.5 in the ammonia elimination reaction route, distinct from the typical pH ranges of most PALs and TALs. Within the exploration of the ammonia source for the opposite, synthetically valuable ammonia addition reaction, the stability of LaAAL, exhibited a positive correlation with the ammonia concentration, with the highest stability in 4 M ammonium carbamate of unadjusted pH of ~9.5. While the enzyme activity increased with rising temperatures yet, the highest operational stability and highest stationary conversions of LaAAL were observed at 30 °C. The substrate scope analysis highlighted the catalytic adaptability of LaAAL in the hydroamination of diverse cinnamic acids, especially of meta-substituted and di-/multi-substituted analogues, with structural modelling exposing steric clashes between the substrates' ortho-substituents and catalytic site residues. LaAAL showed a predilection for ammonia elimination, while classifying as a tyrosine ammonia-lyase (TAL) among the natural AAL classes. However, its distinctive attributes, such as genomic context, unique substrate spe...

Source: Chembiochem - February 28, 2024 Category: Biochemistry Authors: Raluca Bianca Tomoaiaga Gyoparka Agoston Krisztina Boros Levente Csaba Nagy Monica Ioana Tosa Csaba Paizs Laszlo Csaba Bencze Source Type: research