Mussel adhesion is mediated by foot proteins (mfps) rich in a catecholic amino acid, 3,4-dihydroxyphenylalanine (dopa), capable of forming strong bidentate interactions with a variety of surfaces. A tendency toward facile auto-oxidation, however, often renders dopa unreliable for adhesion. We demonstrate that mussels limit dopa oxidation during adhesive plaque formation by imposing an acidic, r...

The ionophoretic capabilities of dioleoylphosphatidic acid (DOPA) for transporting calcium across phospholipid bilayers have been investigated. Calcium uptake by large unilamellar vesicles is shown to depend on the presence of DOPA. This uptake is sensitive to the nature and concentration of calcium chelators in the vesicle interior, indicating that accumulation results from DOPA-mediated trans...

Mucuna pruriens (Fabaceae), also known as cowitch and velvet bean contains very powerful neurotransmitter precursor L-Dopa. The seeds of Mucuna pruriens accumulate 0.2%-2% L-Dopa in their dry weight. L-Dopa is an amino acid that converts into dopamine. Dopamine is an essential component of our body and it requires for the proper functioning of the brain. The seeds powder of Mucuna pruriens has ...

BACKGROUND Leva-dopa (L-dopa) is the gold-standard treatment for Parkinson's disease (PD). Deep brain stimulation is generally reserved for patients who become refractory to l-dopa treatment. CASE DESCRIPTION We present a male patient with a 9-year course of PD who at 53 years of age preferred deep brain stimulation (DBS) of the subthalamic nucleus over initial l-dopa treatment. The patient a...

Enzymatic oxidation of 3,4-dihydroxyphenyl-L-alanine (L-DOPA) with laccase from Trametes versicolor was investigated. The highest enzyme activity at pH 5.4 and at 25 °C was found. The reaction kinetics and the effect of dissolved oxygen concentration on the reaction rate were evaluated. A mathematical model, comprised of double-substrate Michaelis-Menten kinetics and mass balances for L-DOPA an...

Vanilmandelic, homogentisic and homovanillic acid excretions were studied in parkinsonian patients on and off L-dopa. Vanilmandelic acid excretions were quantitated both by gas-chromatographic and calorimetric methods. A marked increase in the excretion of this acid was demonstrated in the parkinsonian patient as compared to controls. Although vanilmandelic excretion rises under the influence o...

Excitatory amino acid (EAA) receptor-mediated events have recently been implicated in dopaminergic mechanisms of neurotoxicity. 2,4,5-Trihydroxyphenylalanine (6-hydroxy-DOPA, TOPA), the ortho-hydroxylated derivative of the dopamine precursor 2,4-dihydroxyphenylalanine (L-DOPA), has recently been reported to have neurotoxic properties which are blocked by CNQX, a specific antagonist of the AMPA ...

The dopamine precursor L-3,4-dihydroxyphenylalanine (L-DOPA) has been used as an effective drug for treating dopamine depletion-induced Parkinson's disease (PD). However, long-term administration of L-DOPA produces motor complications. L-DOPA has also been found to modify the two key signaling cascades, protein kinase A/dopamine- and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32) and extrac...

This study examined the effects of L-dopa medication in patients with Parkinson's disease on cortical and subcortical blood flow changes during two tasks known to involve frontostriatal circuitry. Eleven patients with Parkinson's disease were scanned on two occasions, one ON L-dopa medication and one OFF L-dopa medication, during performance of the Tower of London planning task and a related te...

Objectives. To characterize the pharmacokinetic profile of levodopa (L-dopa) and carbidopa after repeated doses of the effervescent tablet of melevodopa/carbidopa (V1512; Sirio) compared with standard-release L-dopa/carbidopa in patients with fluctuating Parkinson's disease. Few studies assessed the pharmacokinetics of carbidopa to date. Methods. This was a single-centre, randomized, double-bli...