tailieunhanh - Báo cáo khoa học: Characterization of inhibitory mechanism and antifungal activity between group-1 and group-2 phytocystatins from taro (Colocasia esculenta)

Tarocystatin from Colocasia esculenta, a group-2 phytocystatin, is a defense protein against phytopathogenic nematodes and fungi. It is com-posed of a highly conserved N-terminal region, which is homological to group-1 cystatin, and a repetitive peptide at the C-terminus. | ễFEBS Journal Characterization of inhibitory mechanism and antifungal activity between group-1 and group-2 phytocystatins from taro Colocasia esculenta Ke-Ming Wang1 Senthil Kumar1 Yi-Sheng Cheng1 2 Shripathi Venkatagiri3 Ai-Hwa Yang4 and Kai-Wun Yeh1 1 Institute of Plant Biology NationalTaiwan University Taipei Taiwan 2 Department of Life Science NationalTaiwan University Taipei Taiwan 3 Department of Botany Karnatak University Dharwad India 4 Tainan District of AgriculturalImprovement and Extension Station Councilof Agriculture Tainan Taiwan Keywords allosteric activation anti-fungalactivity cysteine proteinase inhibitor inhibitory kinetics tarocystatin CeCPI Correspondence . Yeh Institute of Plant Biology NationalTaiwan University Taipei 106 Taiwan Fax 886 2 23622703 Tel 886 2 33662536 E-mail ykwbppp@ Received 10 June 2008 revised 5 August 2008 accepted 7 August 2008 doi Tarocystatin from Colocasia esculenta a group-2 phytocystatin is a defense protein against phytopathogenic nematodes and fungi. It is composed of a highly conserved N-terminal region which is homological to group-1 cystatin and a repetitive peptide at the C-terminus. The purified recombinant proteins of tarocystatin such as full-length FL N-terminus Nt and C-terminus Ct peptides were produced and their inhibitory activities against papain as well as their antifungal effects were investigated. Kinetic analysis revealed that FL peptide exhibited mixed type inhibition Kia pm and Kib pm and Nt peptide showed competitive inhibition Ki pm whereas Ct peptide possessed weak papain activation properties. A shift in the inhibitory pattern from competitive inhibition of Nt peptide alone to mixed type inhibition of FL peptide implied that the Ct peptide has an regulatory effect on the function of FL peptide. Based on the inhibitory kinetics of FL group-2 and Nt group-1 peptides on papain activity an inhibitory mechanism of group-2 .

TÀI LIỆU LIÊN QUAN
TỪ KHÓA LIÊN QUAN