Increased beta-carboline 9N-methyltransferase activity in the frontal cortex in Parkinson's disease.

Abstract

Enzymatic beta-carboline N-methyltransferase activities generate N-methylated beta-carbolinium cations that are analogs of the parkinsonian-producing neurotoxin MPP+. We measured beta-carboline-2N-methyltransferase and beta-carboline-9N-methyltransferase activities in the supernatant and particulate fractions from postmortem human brains. These N-methyltransferase activities were assessed in the substantia nigra, putamen, and frontal cortex from control and Parkinson's disease cases. No significant differences were measured in any brain region in particulate and supernatant fraction beta-carboline 2N-methyltransferase activity or particulate fraction beta-carboline 9N-methyltransferase activity. Likewise, supernatant fraction beta-carboline 9N-methyltransferase activity was similar in the putamen and substantia nigra from Parkinson's disease and control cases. Unexpectedly, supernatant fraction beta-carboline 9N-methyltransferase activity was increased fourfold in Parkinson's disease frontal cortex (P < 0.05), suggesting that beta-carboline N-methylation may play a role in Parkinson's disease.

• Authors: D A Gearhart, M A Collins, J M Lee, E J Neafsey
• Journal: Neurobiology of disease (Neurobiol Dis) Vol. 7 Issue 3 Pg. 201-11 (Jun 2000) ISSN: 0969-9961 [Print] United States
• PMID: 10860785 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
• Copyright: Copyright 2000 Academic Press.

Chemical References

• Methyltransferases
• beta-carboline 9N-methyltransferase
• beta-carboline-2-N-methyltransferase

Topics

• Aged
• Aged, 80 and over
• Cadaver
• Female
• Frontal Lobe (enzymology)
• Humans
• Male
• Methyltransferases (metabolism)
• Parkinson Disease (enzymology)
• Reference Values
• Tissue Distribution