tailieunhanh - Báo cáo khoa học: Specific degradation of H. pylori urease by a catalytic antibody light chain

Catalytic antibodies capable of digesting crucial proteins of pathogenic bac-teria have long been sought for potential therapeutic use. Helicobacter pyloriurease plays a crucial role for the survival of this bacterium in the highly acidic conditions of human stomach. The HpU-9 monoclonal anti-body (mAb) raised againstH. pyloriurease recognized thea-subunit of the urease, but only slightly recognized theb-subunit. However, when isolated both the light and the heavy chains of this antibody were mostly bound to the b-subunit | ềFEBS Journal Specific degradation of H. pylori urease by a catalytic antibody light chain Emi Hifumi1 2 Kenji Hatiuchi2 Takuro Okuda2 Akira Nishizono3 Yoshiko Okamura1 2 and Taizo Uda1 2 1 PrefecturalUniversity of Hiroshima Faculty of Bioscience and Environment Hiroshima Japan 2 CREST of JST Japan Science and Technology Corporation Saitama Japan 3 Oita University Faculty of Medicine Oita Japan Keywords catalytic antibody light chain Helicobacter pylori urease proteolysis Correspondence T. Uda Faculty of Bioscience and Environment PrefecturalUniversity of Hiroshima Shobara Hiroshima 727-0023 Japan Fax 81 824 74 0191 Tel 81 824 74 1756 E-mail uda@ Received 29 April2005 revised 7 July 2005 accepted 18 July 2005 doi Catalytic antibodies capable of digesting crucial proteins of pathogenic bacteria have long been sought for potential therapeutic use. Helicobacter pylori urease plays a crucial role for the survival of this bacterium in the highly acidic conditions of human stomach. The HpU-9 monoclonal antibody mAb raised against H. pylori urease recognized the a-subunit of the urease but only slightly recognized the b-subunit. However when isolated both the light and the heavy chains of this antibody were mostly bound to the b-subunit. The cleavage reaction catalyzed by HpU-9 light chain HpU-9-L followed the Michaelis-Menten equation with a Km of X 10 5 M and a kcat of min-1 suggesting that the cleavage reaction was enzymatic. In a cleavage test using H. pylori urease HpU-9-L efficiently cleaved the b-subunit but not the a-subunit indicating that the degradation by HpU-9-L had a specificity. The cleaved peptide bonds in the b-subunit were L121-A122 E124-G125 S229-A230 y241-D242 and M262-A263. BSA was hardly cleaved by HpU-9-L again indicating the digestion by HpU-9-L was specific. In summary we succeeded in the preparation of a catalytic antibody light chain capable of specifically digesting the b-subunit of H.

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.