. Author manuscript; available in PMC: 2009 Aug 17.

Published in final edited form as: J Biol Chem. 1999 Dec 17;274(51):36321–36327. doi: 10.1074/jbc.274.51.36321

TABLE II. Calpain inhibition blocks platelet spreading.

The quantitation of platelet spreading on glass coverslips was compared at varying concentrations of inhibitor. The uninhibited extent of spreading was determined from peptide vehicle (150 mm HEPES-KOH, pH 7.4), in the case of calpastat and calpastat-Ala, or Me₂SO vehicle, in the case of calpeptin, MDL, and E64d. NI indicates that no inhibition of spreading occurred following treatment of platelets with calpastat-Ala, or following lysosomal inhibition with NH₄Cl. The distribution of spread and unspread platelets is bimodal under these conditions.

Inhibitor	IC₅₀
	µm
Calpastat	35
Calpastat-Ala	NI
Calpeptin	200
MDL	200
E64d	>250
NH₄Cl (10 mm)	NI