Human plasma kallikrein. A rapid purification method with high yield

Area of Science:

• Biochemistry
• Enzymology
• Proteomics

Background:

• Human plasma kallikrein is a crucial enzyme in the kinin-kallikrein system.
• Previous isolation methods were complex and yielded less active enzyme.

Purpose of the Study:

• To develop a simple and efficient method for isolating pure and active human plasma kallikrein.
• To characterize the purified enzyme's properties and specific activity.

Main Methods:

• Plasma treatment with methylamine to inactivate alpha 2-macroglobulin.
• Enzyme adsorption using soya-bean trypsin inhibitor-Sepharose 4B and elution.
• Purification via immunoadsorption and gel chromatography (Ultrogel AcA 44).

Main Results:

• Obtained 3 mg of kallikrein from 400 ml plasma (35% yield).
• Purified enzyme demonstrated homogeneity via electrophoresis and immunological assays.
• Achieved higher specific activities against synthetic substrates than previously reported.
• Identified two forms (88,000 and 86,000 Da) composed of three disulfide-linked chains.

Conclusions:

• The developed method provides a simple, high-yield isolation of active human plasma kallikrein.
• The purified enzyme exhibits superior specific activity and a complex subunit structure.
• This isolation technique facilitates further research into kallikrein's biological roles.