Download MendeleyThe crystal structure of the novel snake venom plasminogen activator TSV-PA: a prototype structure for snake venom serine proteinases.
Parry, M.A., Jacob, U., Huber, R., Wisner, A., Bon, C., Bode, W.(1998) Structure 6: 1195-1206
- PubMed: 9753698
- DOI: https://doi.org/10.1016/s0969-2126(98)00119-1
- Primary Citation of Related Structures:
1BQY - PubMed Abstract:
Trimeresurus stejnejeri venom plasminogen activator (TSV-PA) is a snake venom serine proteinase that specifically activates plasminogen. Snake venom serine proteinases form a subfamily of trypsin-like proteinases that are characterised by a high substrate specificity and resistance to inhibition. Many of these venom enzymes specifically interfere with haemostatic mechanisms and display a long circulating half-life. For these reasons several of them have commercial applications and are potentially attractive pharmacological tools. The crystal structure of TSV-PA has been determined to 2.5 A resolution and refined to an R factor of 17.8 (R free, 24.4). The enzyme, showing the overall polypeptide fold of trypsin-like serine proteinases, displays unique structural elements such as the presence of a phenylalanine at position 193, a C-terminal tail clamped via a disulphide bridge to the 99-loop, and a structurally conserved Asp97 residue. The presence of a cis proline at position 218 is in agreement with evolutionary relationships to glandular kallikrein. We postulate that Phe 193 accounts for the high substrate specificity of TSV-PA and renders it incapable of forming a stable complex with bovine pancreatic trypsin inhibitor and other extended substrates and inhibitors. Mutational studies previously showed that Asp97 is crucial for the plasminogenolytic activity of TSV-PA, here we identify the conservation of Asp97 in both types of mammalian plasminogen activator - tissue-type (tPA) and urokinase-type (uPA). It seems likely that Asp97 of tPA and uPA will have a similar role in plasminogen recognition. The C-terminal extension of TSV-PA is conserved among snake venom serine proteinases, although its function is unknown. The three-dimensional structure presented here is the first of a snake venom serine proteinase and provides an excellent template for modelling other homologous family members.
Organizational Affiliation:
Max-Planck Institute of Biochemistry Department for Structural Research Am Klopferspitz 18a, 82152, Martinsried, Germany parry@biochem.mpg.de
