Chemical shift assignments of the canecystatin-1 from Saccharum officinarum

Cystatins are cysteine proteases inhibitors that are widely distributed among insects, mammalians and plants. Here we report the complete resonance assignment of canecystatin-1 from Saccharum officinarum obtained by heteronuclear multidimensional high-resolution nuclear magnetic resonance spectroscopy. The consensus chemical shift index was calculated and showed the presence of one α-helix (residues 27–43) and three β-strands (residues 48–74, 78–89 and 94–104), a secondary structure pattern that suggests a domain-swapped structure as presented by stefin B and human cystatin C, opposed to the monomeric structure yet found in other phytocystatins like oryza and pineapple cystatin.