Purification and properties of a human seminal proteinase

Area of Science:

• Biochemistry
• Reproductive Biology
• Enzymology

Background:

• Human seminal plasma contains enzymes influencing sperm function.
• A specific proteinase has been identified that accelerates sperm migration in cervical mucus.
• Understanding this enzyme's properties is crucial for reproductive science.

Purpose of the Study:

• To purify and characterize a proteinase from human seminal plasma.
• To investigate its enzymatic properties and compare them to known enzymes like chymotrypsin.
• To establish a method for its effective purification.

Main Methods:

• Purification involved three steps: ammonium sulfate fractionation, CM-cellulose chromatography, and gel filtration.
• Enzyme activity was assayed using substrates like casein and hemoglobin.
• Enzyme properties such as pH optimum, molecular weight, and inhibition by di-isopropyl phosphofluoridate were determined.

Main Results:

• A 25-fold purification of the proteinase was achieved.
• The enzyme exhibits a pH optimum of 7.5-8.0 and a molecular weight of 33,000.
• It shows substrate preference for casein and hemoglobin but is unaffected by di-isopropyl phosphofluoridate, distinguishing it from chymotrypsin.

Conclusions:

• The purified enzyme is a chymotrypsin-like proteinase found in human seminal plasma.
• Its unique properties suggest a specific role in sperm function and cervical mucus interaction.
• The purification method developed is effective for isolating this biologically significant enzyme.