Affordable Access

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

Authors
Type
Published Article
Journal
FEBS Letters
0014-5793
Publisher
Wiley Blackwell (John Wiley & Sons)
Publication Date
Volume
352
Issue
2
Pages
251–257
Identifiers
PMID: 7925983
Source
Medline
License
Unknown

Abstract

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 degrees 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 beta-sheet with residues 22-28 and 32-38, and an alpha-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 beta-sheet and the C-terminal alpha-helix as well as the N-terminal 20-residue segment preceding the beta-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.

Statistics

Seen <100 times