Purification and characterization of human prostatic acid phosphatase

Area of Science:

• Biochemistry
• Enzymology
• Immunochemistry

Background:

• Human prostatic acid phosphatase (PAP) is an enzyme implicated in various physiological and pathological processes.
• Understanding the structural and immunological properties of PAP is crucial for its study.

Purpose of the Study:

• To purify human prostatic acid phosphatase (PAP) to homogeneity.
• To characterize its molecular weight, subunit composition, and antigenic specificity.
• To investigate the immunological identity of different PAP isozymes.

Main Methods:

• Enzyme purification using CM-Sephadex, Con A affinity chromatography, and gel filtration.
• Determination of molecular weight (M.W.) and subunit M.W.
• Isozyme separation via DEAE-Sephadex chromatography.
• Immunochemical analysis including immunodiffusion, neuraminidase digestion, quantitative precipitin, and inhibition assays.

Main Results:

• Homogeneous PAP was obtained with a M.W. of 100,000 and subunit M.W. of 48,000.
• Two major chromatographic isozymic forms of PAP were separated.
• Both isozymes were immunologically identical, even after neuraminidase treatment.
• Enzyme specificity was attributed to the protein moiety, while carbohydrate residues contributed to charge heterogeneity.

Conclusions:

• Human prostatic acid phosphatase (PAP) exhibits charge heterogeneity due to its carbohydrate residues.
• The immunological specificity of PAP resides in its protein component.
• The purified PAP and its separated isozymes are immunologically indistinguishable.