caa a22 4500 477136605 CHVBK 20180405111720.0 cr unu---uuuuu 170330e19970201xx s 000 0 eng 10.1023/A:1018650119152 doi (NATIONALLICENCE)springer-10.1023/A:1018650119152 Quantitation of chemical exchange rates using pulsed-field-gradient diffusion measurements [Elektronische Daten] [Michael Andrec, James Prestegard] A new approach to the quantitation of chemical exchange rates is presented, and its utility isillustrated with application to the exchange of protein amide protons with bulk water. Theapproach consists of a selective-inversion exchange HMQC experiment in which a short spinecho diffusion filter has been inserted into the exchange period. In this way, the kinetics ofexchange are encoded directly in an apparent diffusion coefficient which is a function of theposition of the diffusion filter in the pulse sequence. A detailed theoretical analysis of thisexperiment indicates that, in addition to the measurement of simple exchange rates, theexperiment is capable of measuring the effect of mediated exchange, e.g. the transfer ofmagnetization from bulk water to an amide site mediated by an internal bound water moleculeor a labile protein side-chain proton in fast exchange with bulk water. Experimental resultsfor rapid water/amide exchange in acyl carrier protein are shown to be quantitativelyconsistent with the exchange rates measured using a selective-inversion exchange experiment. Kluwer Academic Publishers, 1997 Acyl carrier protein nationallicence Translational diffusion nationallicence Spin echo nationallicence Amide exchange nationallicence Bound water nationallicence Andrec Michael Department of Chemistry, Yale University, P.O. Box 208107, 06520-8107, New Haven, CT, U.S.A aut Prestegard James Department of Chemistry, Yale University, P.O. Box 208107, 06520-8107, New Haven, CT, U.S.A aut Journal of Biomolecular NMR Kluwer Academic Publishers 9/2(1997-02-01), 136-150 0925-2738 9:2<136 1997 9 10858 https://doi.org/10.1023/A:1018650119152 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1018650119152 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Andrec Michael Department of Chemistry, Yale University, P.O. Box 208107, 06520-8107, New Haven, CT, U.S.A aut NATIONALLICENCE 700 1- Prestegard James Department of Chemistry, Yale University, P.O. Box 208107, 06520-8107, New Haven, CT, U.S.A aut NATIONALLICENCE 773 0- Journal of Biomolecular NMR Kluwer Academic Publishers 9/2(1997-02-01), 136-150 0925-2738 9:2<136 1997 9 10858 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer