NMR solution structure of the recombinant tick anticoagulant protein (rTAP), a factor Xa inhibitor from the tick Ornithodoros moubata

FEBS Letters

Güntert, P.²  Grossenbacher, H.¹  Antuch, W.²  Hawthorne, T.¹  Wüthrich, K.²  Billeter, M.² 

[1] Biotechnology Department, Ciba-Geigy AG, CH-4002 Basel, Switzerland;Institut für Molekularbiologie und Biophysik, Eidgenössische Technische Hochschule-Hönggerberg, CH-8093 Zürich, Switzerland

关键词: Tick anticoagulant protein;    Protein structure;    Nuclear magnetic resonance;    Blood coagulation;    Proteinase inhibitor;    rTAP;    recombinant tick anticoagulant protein;    BPTI;    bovine pancreatic trypsin inhibitor;    Toxin K;    dendrotoxin K from Dendroaspis polylepis polylepis;    α-DTX;    α-dendrotoxin from Dendroaspis angusticeps;    APPI;    proteinase inhibitor domain of the Alzheimer's amyloid β-protein precursor;    ShPI;    Kunitz-type proteinase inhibitor from Stichodactyla helianthus;    TFA;    trifluoroacetic acid;    NMR;    nuclear magnetic resonance;    2D;    two-dimensional;    2QF-COSY;    2D two-quantum-filtered correlation spectroscopy;    3QF-COSY;    2D three-quantum-filtered correlation spectroscopy;    2Q-spectroscopy;    2D two-quantum spectroscopy;    TOCSY;    2D total correlation spectroscopy;    NOE;    nuclear Overhauser effect;    NOESY;    2D NOE spectroscopy;    E. COSY;    2D exclusive COSY;    3 JHNα;    vicinal spin-spin coupling constant between the amide proton and the α-proton;    3 J αβ;    vicinal spin—spin coupling constant between the α-proton and a β-proton;    CD;    circular dichroism;    ΘMR;    mean residue molar ellipticity;   

DOI  :  10.1016/0014-5793(94)00941-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The solution structure of the recombinant tick anticoagulant protein (rTAP) was determined by ¹H nuclear magnetic resonance (NMR) spectroscopy in aqueous solution at pH 3.6 and 36°C. rTAP is a 60-residue protein functioning as a highly specific inhibitor of the coagulation protease factor Xa, which was originally isolated from the tick Ornithodoros moubata. Its regular secondary structure consists of a two-stranded antiparallel β-sheet with residues 22–28 and 32–38, and an α-helix with residues 51–60. The relative orientation of these regular secondary structure elements has nearly identical counterparts in the bovine pancreatic trypsin inhibitor (BPTI). In contrast, the loop between the β-sheet and the C-terminal α-helix as well as the N-terminal 20-residue segment preceding the β-sheet adopt different three-dimensional folds in the two proteins. These observations are discussed with regard to the implication of different mechanisms of protease inhibition by rTAP and by Kunitz-type protein proteinase inhibitors.

【 授权许可】

Unknown