Influence of Slow Internal Motion in Proteins on Cross-Relaxation Rates Determined by Two-Dimensional Exchange Spectroscopy
نویسندگان
چکیده
Two-dimensional exchange spectroscopy (1-4) has become a very popular tool for the study of dynamic processes in liquids. Originally, chemical exchange (1,5) and cross-relaxation (6,7) were considered to be separate processes. Interference between the two processes (chemical exchange and cross-relaxation) was recognized early (7), but active treatment of the problem (8) was possible only following the development of exchange spectroscopy in the rotating
منابع مشابه
Slow internal protein dynamics from water (1)H magnetic relaxation dispersion.
To probe internal motions in proteins on the 10(-8)-10(-5) s time scale by NMR relaxation, it is necessary to eliminate protein tumbling. Here, we examine to what extent magnetic relaxation dispersion (MRD) experiments on the water (1)H resonance report on protein motions in this time window. We also perform a critical test of two physically distinct mechanisms that have been proposed to explai...
متن کاملTwo-Dimensional Electron Spin Resonance and Slow Motions
The slow rotational dynamics of a polyproline peptide with a nitroxide labeled at one end in a glassy medium is probed using two-dimensional (2D) electron spin resonance (ESR). The contributions to the homogeneous relaxation time, T2, from the overall and/or the internal rotations of the nitroxide is elucidated from the COSY spectra. The use of pure absorption spectra allows the variation of T2...
متن کاملCross-correlated relaxation measurements under adiabatic sweeps: determination of local order in proteins
Adiabatically swept pulses were originally designed for the purpose of broadband spin inversion. Later, unexpected advantages of their utilization were also found in other applications, such as refocusing to excite spin echoes, studies of chemical exchange or fragment-based drug design. Here, we present new experiments to characterize fast (ps-ns) protein dynamics, which benefit from little-kno...
متن کاملSolution structure and backbone dynamics of Calsensin, an invertebrate neuronal calcium-binding protein.
Calsensin is an EF-hand calcium-binding protein expressed by a subset of peripheral sensory neurons that fasciculate into a single tract in the leech central nervous system. Calsensin is a 9-kD protein with two EF-hand calcium-binding motifs. Using multidimensional NMR spectroscopy we have determined the solution structure and backbone dynamics of calcium-bound Calsensin. Calsensin consists of ...
متن کاملAnalysis of the backbone dynamics of the ribonuclease H domain of the human immunodeficiency virus reverse transcriptase using 15N relaxation measurements.
The backbone dynamics of the uniformly 15N-labeled ribonuclease H (RNase H) domain of human immunodeficiency virus (HIV-1) reverse transcriptase have been investigated using two-dimensional inverse-detected heteronuclear 15N-1HNMR spectroscopy. 15N T1, T2, and nuclear Overhauser enhancement (NOE) data were obtained for 107 out of a total of 134 backbone amide groups. The overall rotational corr...
متن کامل