Autolysis of bovine enteropeptidase heavy chain: evidence of fragment 118–465 involvement in trypsinogen activation

FEBS Letters

Mikhailova, Anna G¹  Rumsh, Lev D¹ 

[1] Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya st. 16/10, 117871 Moscow GSP-7, Russia

关键词: Enteropeptidase (enterokinase);    Autolysis;    Trypsinogen activation;    Fusion protein;    Enzyme activity;    EP;    enteropeptidase;    BPI;    basic bovine protease inhibitor;    DI;    enteropeptidase inhibitor from the duodenum;    STI;    soybean trypsin inhibitor;    OVO;    chicken egg white ovomucoid;    BAPNA;    α-N-benzoyl-dl-arginine 4-nitroanilide;    GD4K-NA;    Gly-Asp-Asp-Asp-Asp-Lys-β-naphthylamide;    PrA-P26;    fusion protein composed of the modified protein A and recoverin bound by the EP-specific linker (Asp)4Lys sequence;    Gdn-Bz-ONp;    4′-guanidinobenzoate 4-nitrophenyl ester;    Gdn-Bz-OMum;    4′-guanidinobenzoate 4-methylumbelliferyl ester;    Tris;    tris(hydroxymethyl)aminomethane;    SDS;    sodium dodecyl sulfate;    PAGE;    polyacrylamide gel electrophoresis;    SE-HPLC;    size-exclusion high-performance liquid chromatography;   

DOI  :  10.1016/S0014-5793(98)01656-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Variations in bovine enteropeptidase (EP) activity were shown to result from autolysis caused by the loss of calcium ions; the cleavage sites were determined. The native enzyme preferred its natural substrate, trypsinogen (K _M=2.4 μM), to the peptide and fusion protein substrates (K _M=200 and 125 μM, respectively). On the other hand, the truncated enzyme composed of the C-terminal fragment 466–800 of EP heavy chain and intact light chain did not distinguish these substrates. The results suggest that the N-terminal fragment 118–465 of the enteropeptidase heavy chain contains a secondary substrate-binding site that interacts directly with trypsinogen.

【 授权许可】

Unknown