Chemoproteomic Profiling of Cobalamin-Independent Methionine Synthases in Plants with a Covalent Probe.

Cobalamin-independent methionine synthases (MS) are zinc-binding methyltransferases that catalyze de novo methionine biosynthesis in higher plants, which are enzymes critically involved in seed germination and plant growth. Here, we report a highly selective sulfonyl fluoride-based probe for chemoproteomic profiling of MS enzymes in living systems of the model plant Arabidopsis thaliana, as implemented in in-gel-, mass spectrometry-, and imaging-based platforms. This probe holds promise for facilitating and accelerating fundamental research and industrial application of MS enzymes, particularly in the contexts of MS1/2-targeting herbicide screening and design.