Pillsbury Winthrop LLP
Methods of determining endogenous thrombin potential (ETP) and thrombin substrates for use in said methods
 A method for determining the endogenous thrombin potential of a sample having a total anticoagulant activity of or equivalent to at least 0.07 U ISH/ml, includes using a thrombin substrate or a salt thereof that is soluble in the sample to determine the ETP of the sample. Suitable thrombin substrate include those of the formula P-Val-Xaa-S, in which P is an amino protective group, that is non-aromatic and polar, Val is a valine residue attached via a peptide bond to Xaa, Xaa is an amino acid residue comprising a terminal guanidino group or ureido group separated by at least 2 carbon atoms from the peptide backbond the amino acid residue is attached to S and S is a signal group such as a chromophore that can be enzymatically hydrolyzed. Other substrates include substrates comprising the structure Zaa-Pipecolyl-Yaa-S or Zaa-Pro-Yaa-S, wherein Zaa represents D-Phenylalanine, D-Tryptophan or D-Tyrosine, Pro represents proline, Yaa is an amino acid residue other than arginine and S is a signal marker can also be used. The substrates Boc-Gly-Val-Arg-pNA and H-Glu-Gly-Gly-Val-Arg-pNA are also applicable. Furthermore ETP determination methods can be improved by addition of hydroxylamine to the sample to circumvent defibrination of the sample. 
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G01N C12Q Y02P C07K C07K C07K C07K C07K C07K A61K C07K
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Hendrik Coenraad Godefridus Ignatius Dirk Thomas Sigurd
Hemker Tesser Rijkers