JBC, Vol. 250, Issue 19, 7574-7578, Oct, 1975
Acidic protease from human seminal plasma. Purification and some properties of active enzyme and of proenzyme
P. Ruenwongsa and M. Chulavatnatol
A procedure to purify to homogeneity the active form as well as the
proenzyme form of the acidic protease of human seminal plasma is described.
This involved precipitation with ammonium sulfate, chromatography on
diethylaminoethylcellulose, Sephadex G-200, and Sephadex G-100. The
molecular weights of the active form and of the proenzyme were determined
by electrophoresis and gel filtration to be 35,000 and 42,000,
respectively. The proenzyme was more stable than the active form in
alkaline solution and can be converted into the active enzyme under acidic
conditions. The active form of the acidic protease can hydrolyze
hemoglobin, N,N'-dimethylcasein, N-acetyl-L-phenylalanyl-L-diiodotyrosine,
and N-benzyloxycarbonyl-L-glutamyl-L-phenylalanine, but cannot hydrolyze
bovine serum albumin, ovalbumin, N-benzyloxycarbonyl-L-glutamyl-L-tyrosine.
The active form was also inhibited by p-bromophenacyl bromide and
1,2-epoxy-3-(p-nitrophenoxy)propane.