tailieunhanh - Báo cáo khoa học: "Expression and characterization of the flavoprotein domain of gp91phox"

Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Expression and characterization of the flavoprotein domain of gp91phox | J. Vet. Sci. 2000 1 1 19-26 JOURNAL OF Veterinary Science Expression and characterization of the flavoprotein domain of gp91p ox Chang-Hoon Han and Mun-Han Lee1 Department of Biochemistry Swiss Federal Institute of Technology in Zurich Universitatstrasse 16 8092 Zurich Switzerland Department of Biochemistry College of Veterinary Medicine Seoul National University Suwon 441-744 Korea Truncated forms of gp91p ox were expressed in E. coli in which the N-terminal hydrophobic transmembrane region was replaced with a portion of the highly soluble bacterial protein thioredoxin TRX . TRX-gp91p ox 306-569 which contains the putative FAD and NADPH binding sites showed NADPH-dependent NBT nitroblue tetrazolium reductase activity whereas TRX-gp91p ox 304-423 and TRX-gp91p ox 424-569 were inactive. Activity saturated at about a 1 1 molar ratio of FAD to TRX-g 9r o 306569 and showed the same Km for NADPH as that for superoxide generating activity by the intact enzyme. Activity was not inhibited by superoxide dismutase indicating that it was not mediated by superoxide but was blocked by an inhibitor of the respiratory burst oxidase diphenylene iodonium DPI . In the presence of Rac1 the cytosolic regulatory protein p67p ox stimulated the NBT reductase activity but p47p ox had no effect. Truncated p67 x containing the activation domain residues 199210 stimulated activity approximately 2-fold whereas forms mutated or lacking this region failed to stimulate the activity. Our data indicate that 1 TRX-gp91p ox 306569 contains the binding sites for both pyridine and flavin nucleotides 2 this flavoprotein domain shows NBT reductase activity and 3 the flavin-binding domain of gp91p ox is the target of regulation by the activation domain of p67p ox. Key words gp91phox FAD and NADPH binding sites NBT reductase activity. Introduction Neutrophils and macrophages produce superoxide O2 and secondary reactive oxygen species H2O2 HOCl that participate in killing of phagocytized microorganisms 1 7

TÀI LIỆU LIÊN QUAN
TỪ KHÓA LIÊN QUAN
crossorigin="anonymous">
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.