A combination of two-dimensional (2D) total correlation spectroscopy (TOCSY) and nuclear Overhauser enhancement and exchange spectroscopy (NOESY) has been used to assign the heme proton signals of cytochrome c(3) from Desulfovibrio vulgaris Miyazaki F in the fully reduced state. The sequence-specific assignment of the four hemes was achieved by following chemical exchange connectivities of the heme methyl signals from the fully oxidized to fully reduced states in 2D exchange spectra. Combining the results by one-dimensional saturation transfer and 2D exchange experiments, the chemical shifts of the 14 heme methyl signals out of 16 were determined for the five macroscopic oxidation states. The result showed that two methyl signals of heme 3 behave unusually in terms of the intermediate chemical shifts. The assignment was also made for aromatic residues except for Phe20 and eight-coordinated histidines. On the basis of these assignments and nuclear Overhauser effects among these signals, the heme architectures in different states were discussed.