Proteolytische activiteit bij neutrale pH in rundermilt

Intracellular enzymes, hydrolysing proteins optimally at acid pH values
(acid proteases), have been studied in detail by several investigators. The
existence of proteolytic activity at neutral pH in animal tissue extracts, on
the other hand, has often been mentioned, but with few reports on the
isolation, separation or characterization of the enzymes concerned. This is partly
due to the fact that, the activities at acid pH values are higher than those at
neutral pH, and also, due to the rather elusive nature of the enzyme(s)
assumed to be active at neutral pH. Our studies were aimed at (I) the
demonstration of the proteolytic activity, possibly present in beef spleen at neutral
pH, and more especially, (2) the possible existence of an endopeptidase,
active at neutral or slightly alkaline pH values.