Three-dimensional solution structure of oryzacystatin-I, a cysteine proteinase inhibitor of the rice, Oryza sativa L. japonica

Biochemistry. 2000 Dec 5;39(48):14753-60. doi: 10.1021/bi0006971.

Abstract

The three-dimensional structure of oryzacystatin-I, a cysteine proteinase inhibitor of the rice, Oryza sativa L. japonica, has been determined in solution at pH 6.8 and 25 degrees C by (1)H and (15)N NMR spectroscopy. The main body (Glu13-Asp97) of oryzacystatin-I is well-defined and consists of an alpha-helix and a five-stranded antiparallel beta-sheet, while the N- and C-terminal regions (Ser2-Val12 and Ala98-Ala102) are less defined. The helix-sheet architechture of oryzacystatin-I is stabilized by a hydrophobic cluster formed between the alpha-helix and the beta-sheet and is considerably similar to that of monellin, a sweet-tasting protein from an African berry, as well as those of the animal cystatins studied, e.g., chicken egg white cystatin and human stefins A and B (also referred to as human cystatins A and B). Detailed structural comparison indicates that oryzacystatin-I is more similar to chicken cystatin, which belongs to the type-2 animal cystatins, than to human stefins A and B, which belong to the type-1 animal cystatins, despite different loop length.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cystatins / chemistry*
  • Cysteine Proteinase Inhibitors / chemistry*
  • Models, Molecular
  • Molecular Sequence Data
  • Nitrogen Isotopes
  • Nuclear Magnetic Resonance, Biomolecular
  • Oryza*
  • Plant Proteins / chemistry
  • Protons
  • Sequence Homology, Amino Acid

Substances

  • Cystatins
  • Cysteine Proteinase Inhibitors
  • Nitrogen Isotopes
  • Plant Proteins
  • Protons