Structure and protein design of a human platelet function inhibitor

Cell. 2004 Mar 5;116(5):649-59. doi: 10.1016/s0092-8674(04)00172-2.

Abstract

Hematophagous arthropods secrete a salivary apyrase that inhibits platelet activation by catabolizing ADP released from damaged tissues and blood cells. We report the X-ray crystal structures of a human enzyme of the soluble apyrase family in its apo state and bound to a substrate analog. The structures reveal a nucleotide binding domain comprising a five-blade beta propeller, binding determinants of the substrate and the active site, and an unusual calcium binding site with a potential regulatory function. Using a comparative structural biology approach, we were able to redesign the human apyrase so as to enhance its ADPase activity by more than 100-fold. The engineered enzyme is a potent inhibitor of platelet aggregation and may serve as the basis for the development of a new class of antithrombotic agents.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Apyrase / chemistry*
  • Apyrase / metabolism*
  • Binding Sites
  • Blood Platelets / physiology*
  • Calcium / metabolism
  • Crystallography, X-Ray
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Platelet Aggregation / physiology
  • Platelet Aggregation Inhibitors / chemistry*
  • Platelet Aggregation Inhibitors / metabolism*
  • Protein Conformation*
  • Sequence Alignment
  • Substrate Specificity

Substances

  • Platelet Aggregation Inhibitors
  • Apyrase
  • Calcium

Associated data

  • PDB/1S18
  • PDB/1S1D