Initial Kinetic Characterization of Sterile Alpha and Toll/Interleukin Receptor Motif-Containing Protein 1
Department of Biochemistry and Molecular Pharmacology; Program in Chemical Biology; Graduate School of Biomedical Sciences; Thompson Lab
Amino Acids, Peptides, and Proteins | Biochemistry | Enzymes and Coenzymes | Medicinal-Pharmaceutical Chemistry | Molecular and Cellular Neuroscience | Nervous System Diseases | Nucleic Acids, Nucleotides, and Nucleosides
Sterile alpha and toll/interleukin receptor (TIR) motif-containing protein 1 (SARM1) plays a pivotal role in triggering the neurodegenerative processes that underlie peripheral neuropathies, traumatic brain injury, and neurodegenerative diseases. Importantly, SARM1 knockdown or knockout prevents degeneration, thereby demonstrating that SARM1 is a promising therapeutic target. Recently, SARM1 was shown to promote neurodegeneration via its ability to hydrolyze NAD(+), forming nicotinamide and ADP ribose (ADPR). Herein, we describe the initial kinetic characterization of full-length SARM1, as well as the truncated constructs corresponding to the SAM(1-2)TIR and TIR domains, highlighting the distinct challenges that have complicated efforts to characterize this enzyme. Moreover, we show that bacterially expressed full-length SARM1 (kcat/KM = 6000 +/- 2000 M(-1) s(-1)) is at least as active as the TIR domain alone (kcat/KM = 1500 +/- 300 M(-1) s(-1)). Finally, we show that the SARM1 hydrolyzes NAD(+) via an ordered uni-bi reaction in which nicotinamide is released prior to ADPR.
Peptides and proteins, Assays, Inhibitors, Inhibition, Nicotinamide
DOI of Published Version
Loring HS, Icso JD, Nemmara VV, Thompson PR. Initial Kinetic Characterization of Sterile Alpha and Toll/Interleukin Receptor Motif-Containing Protein 1. Biochemistry. 2020 Mar 3;59(8):933-942. doi: 10.1021/acs.biochem.9b01078. Epub 2020 Feb 17. PMID: 32049506. Link to article on publisher's site
Loring HS, Icso JD, Nemmara VV, Thompson PR. (2020). Initial Kinetic Characterization of Sterile Alpha and Toll/Interleukin Receptor Motif-Containing Protein 1. University of Massachusetts Medical School Faculty Publications. https://doi.org/10.1021/acs.biochem.9b01078. Retrieved from https://escholarship.umassmed.edu/faculty_pubs/1664