title: An Integrated Approach to Unique NMR Assignment of Methionine Methyl Resonances in Proteins.
abstract: The application of methyl nuclear magnetic resonance (NMR) spectroscopy in protein side-chain structural studies offers unique advantages of greater peak sensitivity, even for high-molecular-weight proteins. Traditionally, the utility of methyl NMR has often been limited by the difficulty in assigning the methyl resonances. Herein, a mass spectrometry (MS)-assisted strategy to assign the methyl resonances of methionine residues is presented. The strategy involves partially oxidizing the methionine and quantifying the oxidation level by both NMR and liquid chromatography-mass spectrometry (LC-MS). The NMR assignment of methyl resonances of methionine is made by correlating the quantitative results obtained from both NMR and MS. The method has been successfully demonstrated using the proteins hen egg-white lysozyme (HEWL) and porcine pepsin. The technique described herein can help facilitate the application of methyl NMR as a useful tool to study protein structure, dynamics, and interactions.
authors.affiliation: Momenta Pharmaceuticals Inc. , 675 West Kendall Street, Cambridge, Massachusetts 02142, United States.
authors.forename: Fei
authors.initials: F
authors.lastname: Yu
authors.affiliation: Momenta Pharmaceuticals Inc. , 675 West Kendall Street, Cambridge, Massachusetts 02142, United States.
authors.forename: Jing
authors.initials: J
authors.lastname: Qiao
authors.affiliation: Momenta Pharmaceuticals Inc. , 675 West Kendall Street, Cambridge, Massachusetts 02142, United States.
authors.forename: John
authors.initials: J
authors.lastname: Robblee
authors.affiliation: Momenta Pharmaceuticals Inc. , 675 West Kendall Street, Cambridge, Massachusetts 02142, United States.
authors.forename: Desiree
authors.initials: D
authors.lastname: Tsao
authors.affiliation: Momenta Pharmaceuticals Inc. , 675 West Kendall Street, Cambridge, Massachusetts 02142, United States.
authors.forename: James
authors.initials: J
authors.lastname: Anderson
authors.affiliation: Momenta Pharmaceuticals Inc. , 675 West Kendall Street, Cambridge, Massachusetts 02142, United States.
authors.forename: Ishan
authors.identifier: 0000-0002-5036-6778
authors.initials: I
authors.lastname: Capila
mesh_terms: D000818:Animals; D002645:Chickens; D002851:Chromatography, High Pressure Liquid; D018360:Crystallography, X-Ray; D013058:Mass Spectrometry; D008715:Methionine / Q000737:chemistry*; D009113:Muramidase / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010434:Pepsin A / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D013552:Swine
chemical_list: D008715:Methionine; C421864:hen egg lysozyme; D009113:Muramidase; D010434:Pepsin A