Methods for the determination of glandular kallikrein by means of a chromogenic tripeptide substrate.

A chromogenic peptide substrate H-D-Val-Leu-Arg-pNA (S-2266) has been used for the determination of glandular kallikrein derived from pancreas, urine and saliva. The conditions used have been optimized. The methods developed are simple and shown to have good reproducibility.

The use of a quantitative assay in endotoxin testing.

By utilizing Limulus Amebocyte Lysate (LAL) and a chromogenic peptide substrate it is now possible to determine endotoxin concentrations quantitatively down to 10 EU/L (1 pg/mL) in a two stage assay. The optimal reaction conditions found for the two stages of the method, the endotoxin reaction with LAL and the measurement of the activation with the chromogenic substrate, are briefly described. The properties of the final kit reagents have also been investigated and the results are included. Finally, the usefulness of the present method is demonstrated by results obtained from testing therapeutical products as well as clinical plasmas. Some factors which may be critical in the performance of the assay are discussed.

Methods for determination of prekallikrein in plasma, glandular kallikrein and urokinase.

New chromogenic tripeptide substrates have been used for the determination of kallikreins and urokinase. The conditions have been optimized. It is possible to determine prekallikrein in plasma after activation with Cephotest. No significant loss in activity caused by plasma kallikrein inhibitors is observed at the dilutions used.

Methods for determination of plasmin, antiplasmin and plasminogen by means of substrate S-2251.

The chromogenic substrate S-2251 (H-D-Val-Leu-Lys-pNA), a selective and sensitive substrate for plasmin activity, has made it possible to develop simple and reproducible methods for the determination of antiplasmin and plasminogen in human plasma. These methods have been optimized and studied in detail and found to be very specific for the respective factors.