Download MendeleyMetabolism of Cysteine Conjugates and Production of Flavor Sulfur Compounds by a Carbon-Sulfur Lyase from the Oral Anaerobe Fusobacterium nucleatum.
Neiers, F., Gourrat, K., Canon, F., Schwartz, M.(2022) J Agric Food Chem 70: 9969-9979
- PubMed: 35920882
- DOI: https://doi.org/10.1021/acs.jafc.2c01727
- Primary Citation of Related Structures:
7QUG - PubMed Abstract:
Flavor perception is a key factor in the acceptance or rejection of food. Aroma precursors such as cysteine conjugates are present in various plant-based foods and are metabolized into odorant thiols in the oral cavity. To date, the involved enzymes are unknown, despite previous studies pointing out the likely involvement of carbon-sulfur lyases (C-S lyases) from the oral microbiota. In this study, we show that saliva metabolizes allyl-cysteine into odorant thiol metabolites, with evidence suggesting that microbial pyridoxal phosphate-dependent C-S lyases are involved in the enzymatic process. A phylogenetic analysis of PatB C-S lyase sequences in four oral subspecies of Fusobacterium nucleatum was carried out and led to the identification of several putative targets. FnaPatB1 from F. nucleatum subspecies animalis , a putative C-S lyase, was characterized and showed high activity with a range of cysteine conjugates. Enzymatic and X-ray crystallographic data showed that FnaPatB1 metabolizes cysteine derivatives within a unique active site environment that enables the formation of flavor sulfur compounds. Using an enzymatic screen with a library of pure compounds, we identified several inhibitors able to reduce the C-S lyase activity of FnaPatB1 in vitro, which paves the way for controlling the release of odorant sulfur compounds from their cysteine precursors in the oral cavity.
Organizational Affiliation:
Centre for Taste and Feeding Behavior (CSGA), INRAE, CNRS, University of Burgundy-Franche Comté, Institut Agro, F-21000 Dijon, France.
