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Updated: Aug 9, 2026

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
HACACO revisited: residual dipolar coupling measurements and resonance assignments in proteins
Daniel O Cicero1, Gian Marco Contessa, Maurizio Paci
1Department of Chemical Science and Technology, University of Rome "Tor Vergata," Italy.
Abstract:
The revisited version of the HACACO experiment here presented, is more robust and straightforward to implement and continues to be, to a greater extent, a convenient tool for protein backbone resonance assignment. Additionally, it turns out to be a sensitive and accurate method to measure C(alpha)-H(alpha) residual dipolar couplings (RDCs). The performance of our new pulse scheme for measurement of RDCs was tested on two proteins with different secondary structures: one characterized by a high beta-sheet content, the second dominated by the presence of alpha-helices. In both examples the new method provided significantly more accurate data, compared to all previously published 3D techniques.
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