A rapid assay method for catechol-O-methyltransferase activity by flow injection analysis.

Area of Science:

• Biochemistry
• Analytical Chemistry
• Enzymology

Background:

• Catechol-O-methyltransferase (COMT) is a key enzyme in neurotransmitter metabolism.
• Accurate and efficient methods for determining COMT activity are crucial for pharmacological research.

Purpose of the Study:

• To develop and validate a rapid assay for determining purified porcine liver COMT activity.
• To establish a high-throughput method for screening COMT modulators.

Main Methods:

• Flow injection analysis (FIA) coupled with coulometric oxidation and fluorogenic detection.
• Assay based on the measurement of normetanephrine, the O-methylated metabolite of norepinephrine.
• Alumina extraction used to remove excess substrate (norepinephrine).

Main Results:

• The assay demonstrated high throughput, processing up to 200 samples per day.
• Kinetic parameters for COMT were determined: K(m) = 503 microM and V(max) = 4.51 nmol/min/mg protein.
• The method is sensitive and suitable for COMT activity assessment.

Conclusions:

• A rapid and efficient FIA-based assay for COMT activity has been established.
• This assay is valuable for screening potential COMT inhibitors and activators.
• The method offers a significant advantage in terms of sample processing capacity for biochemical studies.