Human seminal plasma proteinase inhibitor: action toward some trypsin-like arginine amidases from humans

Inhibitors on an elastase-like enzyme activity catalyzing Suc-Ala-Ala-Pro-Leu-pNA amidolysis in human seminal plasma

The behavior of some proteinase inhibitors toward the Suc-Ala-Ala-Pro-Leu-pNA amidolytic enzyme activity in human seminal plasma (HSP) was tested. [(2S, 3R)-3-Amino-2-hydroxy-5-methyl-hexanoyl]L-valyl-L-valyl-L-aspartic acid (Amastatin) and 3-[1-[(2-(hydroxymethyl)- -pyrolidinyl)-2-methylpropyl]-carbamoyl] octanohydroxamic acid (Actinonin) showed strong inhibitory effects. No inhibition of this present enzyme activity was seen with anti-human serum (whole), anti-human leukocyte elastase, phenyl-methyl sulfonyl fluoride, Elastatinal, ethyeneglycol bis(beta-aminoethyl ethyl)N,N,N:N'-tetra acetic acid, and [L-3-trans-ethoxycarbonyl-oxirane-2-carbonyl]1-L-leucine(3-methylbutyl)a mido (E-64). No relation was observed between human pancreatic elastase antigen and the Suc-Ala-Ala-Pro-Leu-pNA amidolytic enzyme enzyme activity in HSP. Two peaks of Suc-Ala-Ala-Leu-Pro-pNA amidolytic enzyme activity were separated by Cellulofine GCL-2000 gel filtration and these activities were completely abolished by addition of Amastatin. Suc-Ala-Ala-Pro-Leu-pNA amidolytic enzyme activity in HSP is not an elastase-like metalloproteinase but is rather an acyl amidase-like leucine aminopeptidase.

Fibrinogen-like substance and thrombin-like enzyme in seminal plasma: coagulation system of human semen

This investigation was conducted to examine the presence of fibrinogen-like substance and thrombin-like enzyme in human semen (human seminal plasma) after liquefaction. The human seminal plasma contained small amounts of respective substances which are absorbed on anti-fibrinogen and anti-thrombin III affinity columns, respectively. The thrombin-like enzyme with Gly-Pro-Arg-pNA amidolytic activity was inhibited by human seminal plasma trypsin-like enzyme inhibitor (HSP-TI) and antithrombin III. The fibrinogen-like substance reacted with the thrombin-like enzyme, forming a fibrin-like substance. It would appear that certain aspects of the coagulation process in human semen constitute the same process as the final stage of the blood coagulation system.