biostudies-literatureGill MLNCRR NIH HHSFoundation for the National Institutes of HealthNIGMS NIH HHS443-450https://www.ebi.ac.uk/biostudies/studies/S-EPMC6862771biostudies-literatureUnknown73(8-9)The zero- and double-quantum methyl TROSY Hahn-echo and the methyl ¹H-¹H dipole-dipole cross-correlation nuclear magnetic resonance experiments enable estimation of multiple quantum chemical exchange broadening in methyl groups in proteins. The two relaxation rate constants are established to be linearly dependent using molecular dynamics simulations and empirical analysis of experimental data. This relationship allows chemical exchange broadening to be recognized as an increase in the Hahn-echo relaxation rate constant. The approach is illustrated by analyzing relaxation data collected at three temperatures for E. coli ribonuclease HI and by analyzing relaxation data collected for different cofactor and substrate complexes of E. coli AlkB.Journal of biomolecular NMRDetection of chemical exchange in methyl groups of macromolecules.PMC6862771R01 GM050291GM008281GM089047F32 GM089047P41 GM118302GM50291R35 GM130398S10 RR026540RR026540T32 GM008281GM118302Gill MLHsu APalmer AGfalseDetection of chemical exchange in methyl groups of macromolecules.The zero- and double-quantum methyl TROSY Hahn-echo and the methyl ¹H-¹H dipole-dipole cross-correlation nuclear magnetic resonance experiments enable estimation of multiple quantum chemical exchange broadening in methyl groups in proteins. The two relaxation rate constants are established to be linearly dependent using molecular dynamics simulations and empirical analysis of experimental data. This relationship allows chemical exchange broadening to be recognized as an increase in the Hahn-echo relaxation rate constant. The approach is illustrated by analyzing relaxation data collected at three temperatures for E. coli ribonuclease HI and by analyzing relaxation data collected for different cofactor and substrate complexes of E. coli AlkB.2019-01-01T00:00:00Z2019 Sep2025-04-04T15:03:15.13Z2020-09-05T07:11:20ZS-EPMC68627713140720310.1007/s10858-019-00240-w