title: Resonance assignments and secondary structure of a phytocystatin from Sesamum indicum.
abstract: A cDNA encoding a cysteine protease inhibitor, cystatin was cloned from sesame (Sesamum indicum L.) seed. This clone was constructed into an expression vector and expressed in E. coli and purified to homogeneous. The recombinant sesame cystatin (SiCYS) showed effectively inhibitory activity toward C1 cysteine proteases. In order to unravel its inhibitory action from structural point of view, multidimensional heteronuclear NMR techniques were used to characterize the structure of SiCYS. The full (1)H, (15)N, and (13)C resonances of SiCYS were assigned. The secondary structure of SiCYS was identified by using the assigned chemical shifts of (1)H(α), (13)C(α), (13)C(β), and (13)CO through the consensus chemical shift index (CSI). The results of CSI analysis of SiCYS suggest eight β-strands (residues 33-46, 51-61, 63-75, 80-87, 150-155, 157-169, 172-183, and 192-195) and two α-helices (residues 16-30, and 120-135).
authors: Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien, 974, Taiwan, ROC.
authors: Yu-Jun
authors: YJ
authors: Hu
authors: Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien, 974, Taiwan, ROC.
authors: Deli
authors: D
authors: Irene
authors: Department of Biochemistry, National Yang Ming University, Taipei, 112, Taiwan, ROC.
authors: Chi-Jen
authors: CJ
authors: Lo
authors: Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien, 974, Taiwan, ROC.
authors: Yong-Liang
authors: YL
authors: Cai
authors: Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 402, Taiwan, ROC.
authors: T-C
authors: TC
authors: Tzen
authors: Department of Biochemistry, National Yang Ming University, Taipei, 112, Taiwan, ROC.|Basic Research Division, Medical Research Department, Taipei Veterans General Hospital, Taipei, 112, Taiwan, ROC.
authors: Ta-Hsien
authors: TH
authors: Lin
authors: Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien, 974, Taiwan, ROC. chyan@mail.ndhu.edu.tw.
authors: Chia-Lin
authors: CL
authors: Chyan
mesh_terms: D015891:Cystatins / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010940:Plant Proteins / Q000737:chemistry*; D017433:Protein Structure, Secondary; D066244:Proton Magnetic Resonance Spectroscopy; D031685:Sesamum / Q000378:metabolism*
chemical_list: D015891:Cystatins; D010940:Plant Proteins
keywords: Cystatin; Cysteine protease inhibitor; Phytocystatin; Protein NMR