https://doi.org/10.1351/goldbook.08362
Three-dimensional nuclear magnetic resonance spectroscopy for the assignment of protein structure with nitrogen, carbon and hydrogen dimensions.
Note: The magnetization is passed from \(\ce{^{1}H}\) to \(\ce{^{15}N}\) and then to \(\ce{^{13}CO}\). From here it is transferred to \(\ce{^{13}C\upalpha}\) and the chemical shift is evolved. The magnetization is then transferred back via \(\ce{^{13}CO}\) to \(\ce{^{15}N}\) and \(\ce{^{1}H}\) for detection. This is similar to the HNCA, but is selective for the \(\ce{C\upalpha}\) of the preceding residue.