Partial proteolysis of human L-type phosphofructokinase.

L (liver) type phosphofructokinase subunits purified from human leukocytes are slightly lighter than L subunits from liver and red blood cells. A mild treatment of red blood cell L4 enzyme with subtilisin converts its subunits into forms of similar molecular weight to leukocyte enzyme. From a kinetical point of view, subtilisin-treated L4 phosphofructokinase and leukocyte enzymes are characterized by a decrease of the allosteric properties as compared to non-treated red cell L4 phosphofructokinase.