2026-10-11T08:01:50Z https://api.figshare.com/v2/oai

oai:figshare.com:article/33920647 2026-09-18T05:40:53Z category_8 portal_316 item_type_3 month_year_09_2026

Supplementary file 1_Metabolic versatility of Acinetobacter baumannii: distinct pathways for the utilization of short-, medium- and long-chain acyl-L-carnitines.docx Paula Schwerdhelm (25070320) Kateryna Podrez (25070323) Julian Kaltenhäuser (25070326) Simon Sivov (25070329) Beate Averhoff (796778) Dominik Körner (25070332) Lothar Jänsch (28449) Dieter Jahn (9897) Jürgen Moser (19422040) Microbiology Acinetobacter baumannii acyl-L-carnitine carnitine hydrolase trimethylamine <p>Acinetobacter baumannii is a multidrug-resistant pathogen capable of metabolizing host-derived acyl-L-carnitines, which contributes to its virulence. During A. baumannii growth on acetyl-L-carnitine, L-carnitine was initially released into the growth medium suggesting that acetate is metabolized first. The subsequent uptake of L-carnitine at the end of the exponential phase then facilitates the catabolism of L-carnitine. Involvement of the betaine/choline/carnitine transporter (BCCT) in the uptake of short- and medium-chain acyl-L-carnitines was confirmed through growth experiments using the Δbcct mutant strain. An uncharacterized hydrolase (HMPREF0010_01348) encoded by the L-carnitine degradation gene operon (HMPREF0010_01345 – HMPREF0010_01351) was biochemically identified as a short- and medium-chain acyl-L-carnitine hydrolase (ACH). Its cellular localization in the cytoplasm was demonstrated. The purified ACH exhibited no enzymatic activity toward long-chain acyl-L-carnitines. However, growth experiments revealed that both the wild type and the Δach mutant were able to grow clearly on these substrates, providing evidence for the involvement of an additional, as-yet-uncharacterized enzyme. The cell culture supernatant was used for the chromatographic enrichment of a protein fraction showing robust enzyme activity for the hydrolysis of long-chain acyl-L-carnitines. Proteomic analysis of a partially purified hydrolase fraction and of the A. baumannii secretome revealed the gene product of open reading frame HMPREF0010_02333 as a hydrolase candidate. The respective protein was recombinantly overproduced and purified and its ability to cleave various long-chain acyl-L-carnitines was demonstrated. Based on the substrate specificity of the characterized ACH from the cytosol and the acyl-L-carnitine hydrolase present in the culture supernatant (ACHS), a metabolic model for the versatile utilization of small- medium- and long-chain acyl-L-carnitines by A. baumannii was proposed.</p> 2026-09-18T05:40:53Z Dataset Dataset 10.3389/fmicb.2026.1964901.s001 https://figshare.com/articles/dataset/Supplementary_file_1_Metabolic_versatility_of_Acinetobacter_baumannii_distinct_pathways_for_the_utilization_of_short-_medium-_and_long-chain_acyl-L-carnitines_docx/33920647 CC BY 4.0