Some physicochemical and enzymic properties of selenium-containing abzyme

Area of Science:

• Biochemistry
• Immunology
• Enzymology

Background:

• Glutathione peroxidase (GPX) is crucial for antioxidant defense.
• Abzymes, antibodies with catalytic activity, offer unique therapeutic potential.
• Incorporating selenium into abzymes can enhance their activity.

Purpose of the Study:

• To prepare and characterize a selenium-containing abzyme (Se-abzyme) with GPX activity.
• To evaluate the physicochemical properties, enzymic activity, and stability of the Se-abzyme.
• To compare the Se-abzyme's characteristics with native GPX.

Main Methods:

• Preparation of Se-abzyme with GPX activity.
• Determination of isoelectric point and molecular weight.
• Assessment of optimum pH, temperature, and storage stability.
• Quantification of selenium content using X-ray photoelectron spectroscopy.
• Binding constant determination via ELISA.
• Enzyme inhibition studies using dithiobis(2-nitrobenzoic acid) (DTNB).

Main Results:

• The Se-abzyme exhibited an isoelectric point of 6.95-7.08 and a molecular weight of 158 KD.
• Se-abzyme demonstrated broader optimal pH and temperature ranges than native GPX.
• Enhanced storage stability was observed for Se-abzyme compared to native GPX.
• Selenium content was 5 mol Se/mol abzyme; binding constant was 1.11 x 10(7)M-1.
• DTNB competitively inhibited Se-abzyme with an inhibition constant of 1.25 x 10(-3)M-1.

Conclusions:

• Successfully prepared Se-abzyme with significant GPX activity.
• Se-abzyme possesses superior stability and broader operational ranges compared to native GPX.
• The findings highlight the potential of Se-abzymes in antioxidant therapies.