Figure 3
From: Mammalian plasma fetuin-B is a selective inhibitor of ovastacin and meprin metalloproteinases
Apparent temporary inhibition of trypsin activity by fetuins and their cleavage by trypsin and plasmin. (a) 5 nM trypsin was pre-incubated with fetuin-A or fetuin-B for 10 min and 30 min at 37 °C. After the incubation proteolytic activity was measured with 100 µM fluorogenic substrate Boc-FSR-MCA at 37 °C. 100% activity corresponds to a substrate turnover rate of 10 nM/s. (b) Trypsin and plasmin were incubated with fetuin-A or fetuin-B for the indicated times at 37 °C. The reaction was stopped by boiling in SDS sample buffer for five minutes. Fetuin fragments were detected by immunoblot using homemade polyclonal rabbit antibodies directed against mouse fetuin-A or mouse fetuin-B.
