Peptidases in Human Serum.

Abstract

The peptidase activity of human serum was studied in normal adults and in patients suffering from a number of pathologic conditions, using the Grassmann and Heyde microtitration technique. A cobalt-activatable enzyme was found which in normal subjects splits L-leucylglycylgly-cine (40 C and pH 7.8) at a rate of 6.1-7.8%/hr. Considerably higher rates were observed in cases of puerperal fever and bone fracture. These rates decreased with the progress of healing. The peptidase activity of human serum towards L-glycylleucine was lower (2.3%) and was slightly activated by Mn (0.001 [image]). Glycylglycine was split only in the presence of Co (0.001 [image]).