Rapid and sensitive single-step radiochemical assay for catechol-O-methyltransferase

Area of Science:

• Biochemistry
• Enzyme Assays
• Radiochemistry

Background:

• Catechol-O-methyltransferase (COMT) is a key enzyme in catecholamine metabolism.
• Accurate measurement of COMT activity is crucial for understanding its role in various physiological and pathological processes.
• Existing methods for COMT activity determination can be complex, time-consuming, or lack sensitivity.

Purpose of the Study:

• To develop a simple, rapid, and reliable radiometric assay for determining catechol-O-methyltransferase (COMT) activity.
• To provide a more sensitive alternative to existing COMT assay procedures.

Main Methods:

• The assay utilizes the conversion of catechol to [3H]guaiacol by COMT.
• Key components include Mg2+, adenosine deaminase, and S-adenosyl L-[methyl-3H]methionine.
• Incubation, extraction of [3H]guaiacol into scintillation fluid, and counting are performed in a single scintillation vial.

Main Results:

• A simple, rapid, and reliable radiometric assay for COMT activity was successfully established.
• The assay demonstrated higher sensitivity compared to previous analogous methods.
• The method was effectively applied to measure COMT activity in rat brain and peripheral organs, as well as in human erythrocytes.

Conclusions:

• The described radiometric assay offers a straightforward and sensitive method for quantifying COMT activity.
• This assay is suitable for diverse biological samples, including tissue homogenates and erythrocytes.
• The assay facilitates research into COMT's function in different biological systems.