“…After tryptic digest, peptides were analyzed using liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) and compared with the PL -cultured control using label-free quantification (LFQ) (Figure 2B) (Cox et al., 2014). We detected 15 PLP -DEs (GO term 0030170: PLP binding; Ashburner et al., 2000) significantly enriched upon PL1 labeling in HEK293 compared with the control (Figure 2C and Table S1), which accounts for around 30% of the complete human pool of PLP -binding enzymes (53 reviewed proteins annotated with GO term 0030170: PLP binding within the human proteome [UniProt: 9606]; Ashburner et al., 2000), including members of fold types I, II, and IV (El-Sayed and Shindia, 2012). Several PLP -DEs related to cancer proliferation and tumor development (e.g., SHMT1; Renwick et al., 1998 or cytosolic aspartate aminotransferase, GOT1; Thornburg et al., 2008) or to Parkinson disease (Bras et al., 2008) and atherosclerosis (Park et al., 2008) (serine palmitoyltransferase 2, SPTLC2, and sphingosine-1-phosphate lyase 1, SGPL1) were identified.…”