6g56

Publication Abstract from PubMed

Pyridoxal phosphate (PLP) is an enzyme cofactor required for the chemical transformation of biological amines in many central cellular processes. PLP-dependent enzymes (PLP-DEs) are ubiquitous and evolutionarily diverse, making their classification based on sequence homology challenging. Here we present a chemical proteomic method for reporting on PLP-DEs using functionalized cofactor probes. We synthesized pyridoxal analogues modified at the 2'-position, which are taken up by cells and metabolized in situ. These pyridoxal analogues are phosphorylated to functional cofactor surrogates by cellular pyridoxal kinases and bind to PLP-DEs via an aldimine bond which can be rendered irreversible by NaBH4 reduction. Conjugation to a reporter tag enables the subsequent identification of PLP-DEs using quantitative, label-free mass spectrometry. Using these probes we accessed a significant portion of the Staphylococcus aureus PLP-DE proteome (73%) and annotate uncharacterized proteins as novel PLP-DEs. We also show that this approach can be used to study structural tolerance within PLP-DE active sites and to screen for off-targets of the PLP-DE inhibitor D-cycloserine.

Mining the cellular inventory of pyridoxal phosphate-dependent enzymes with functionalized cofactor mimics.,Hoegl A, Nodwell MB, Kirsch VC, Bach NC, Pfanzelt M, Stahl M, Schneider S, Sieber SA Nat Chem. 2018 Oct 8. pii: 10.1038/s41557-018-0144-2. doi:, 10.1038/s41557-018-0144-2. PMID:30297752^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.