Capture compound mass spectrometry sheds light on the molecular mechanisms of liver toxicity of two Parkinson drugs.
Capture compound mass spectrometry (CCMS) is a novel technology that helps understand the molecular mechanism of the mode of action of small molecules. The Capture Compounds are trifunctional probes: A selectivity function (the drug) interacts with the proteins in a biological sample, a reactivity function (phenylazide) irreversibly forms a covalent bond, and a sorting function (biotin) allows the captured protein(s) to be isolated for mass spectrometric analysis. Tolcapone and entacapone are potent inhibitors of catechol-O-methyltransferase (COMT) for the treatment of Parkinson's disease. We aimed to understand the molecular basis of the difference of both drugs with respect to side effects. Using Capture Compounds with these drugs as selectivity functions, we were able to unambiguously and reproducibly isolate and identify their known target COMT. Tolcapone Capture Compounds captured five times more proteins than entacapone Capture Compounds. Moreover, tolcapone Capture Compounds isolated mitochondrial and peroxisomal proteins. The major tolcapone-protein interactions occurred with components of the respiratory chain and of the fatty acid beta-oxidation. Previously reported symptoms in tolcapone-treated rats suggested that tolcapone might act as decoupling reagent of the respiratory chain (Haasio et al., 2002b). Our results demonstrate that CCMS is an effective tool for the identification of a drug's potential off targets. It fills a gap in currently used in vitro screens for drug profiling that do not contain all the toxicologically relevant proteins. Thereby, CCMS has the potential to fill a technological need in drug safety assessment and helps reengineer or to reject drugs at an early preclinical stage.
Caprotec Bioanalytics GmbH, 12489 Berlin, Germany.
Jenny J
JJ
Fischer
Simon
S
Michaelis
Anna K
AK
Schrey
Olivia Graebner nee
OG
Graebner
Mirko
M
Glinski
Mathias
M
Dreger
Friedrich
F
Kroll
Hubert
H
Koester
D000818:Animals; D000978:Antiparkinson Agents / Q000737:chemistry / Q000633:toxicity*; D001577:Benzophenones / Q000737:chemistry / Q000633:toxicity*; D002394:Catechol O-Methyltransferase / Q000378:metabolism; D065098:Catechol O-Methyltransferase Inhibitors; D002396:Catechols / Q000737:chemistry / Q000633:toxicity*; D056486:Chemical and Drug Induced Liver Injury / Q000201:enzymology / Q000209:etiology* / Q000378:metabolism; D017076:Computer-Aided Design; D004579:Electron Transport; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000633:toxicity*; D005227:Fatty Acids / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D013058:Mass Spectrometry; D008862:Microsomes, Liver / Q000378:metabolism; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000378:metabolism; D008958:Models, Molecular; D015394:Molecular Structure; D009570:Nitriles / Q000737:chemistry / Q000633:toxicity*; D009596:Nitrophenols / Q000737:chemistry / Q000633:toxicity*; D010084:Oxidation-Reduction; D010085:Oxidative Phosphorylation; D020675:Peroxisomes / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D015203:Reproducibility of Results; D000077867:Tolcapone; D018675:Toxicity Tests / Q000379:methods*
D000978:Antiparkinson Agents; D001577:Benzophenones; D065098:Catechol O-Methyltransferase Inhibitors; D002396:Catechols; D004791:Enzyme Inhibitors; D005227:Fatty Acids; D024101:Mitochondrial Proteins; D009570:Nitriles; D009596:Nitrophenols; C071192:entacapone; D000077867:Tolcapone; D002394:Catechol O-Methyltransferase