Molecular engineering and immobilization of lysine decarboxylase for synthesis of 1, 5-diaminopentane: a review / 生物工程学报

1, 5-diaminopentane, also known as cadaverine, is an important raw material for the production of biopolyamide. It can be polymerized with dicarboxylic acid to produce biopolyamide PA5X whose performances are comparable to that of the petroleum-based polyamide materials. Notably, biopolyamide uses renewable resources such as starch, cellulose and vegetable oil as substrate. The production process does not cause pollution to the environment, which is in line with the green and sustainable development strategy. The biosynthesis of 1, 5-diaminopentane mainly includes two methods: the de novo microbial synthesis and the whole cell catalysis. Lysine decarboxylase as the key enzyme for 1, 5-diaminopentane production, mainly includes an inducible lysine decarboxylase CadA and a constituent lysine decarboxylase LdcC. Lysine decarboxylase is a folded type Ⅰ pyridoxal-5' phosphate (PLP) dependent enzyme, which displays low activity and unstable structure, and is susceptible to deactivation by environmental factors in practical applications. Therefore, improving the catalytic activity and stability of lysine decarboxylase has become a research focus in this field, and molecular engineering and immobilization are the mainly approaches. Here, the mechanism, molecular engineering and immobilization strategies of lysine decarboxylase were reviewed, and the further strategies for improving its activity and stability were also prospected, with the aim to achieve efficient production of 1, 5-diaminopentane.

Knockdown of PAICS inhibits malignant proliferation of human breast cancer cell lines

BACKGROUND: Phosphoribosylaminoimidazole carboxylase, phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS), an enzyme required for de novo purine biosynthesis, is associated with and involved in tumorigenesis. This study aimed to evaluate the role of PAICS in human breast cancer, which remains the most frequently diagnosed cancer and the leading cause of cancer-related death among women in less developed countries. RESULTS: Lentivirus-based short hairpin RNA targeting PAICS specifically depleted its endogenous expression in ZR-75-30 and MDA-MB-231 breast cancer cells. Depletion of PAICS led to a significant decrease in cell viability and proliferation. To ascertain the mechanisms through which PAICS modulates cell proliferation, flow cytometry was performed, and it was confirmed that G1-S transition was blocked in ZR-75-30 cells through PAICS knockdown. This might have occurred partly through the suppression of Cyclin E and the upregulation of Cyclin D1, P21, and CDK4. Moreover, PAICS knockdown obviously promoted cell apoptosis in ZR-75-30 cells through the activation of PARP and caspase 3 and downregulation of Bcl-2 and Bcl-xl expression in ZR-75-30 cells. CONCLUSIONS: These findings demonstrate that PAICS plays an essential role in breast cancer proliferation in vitro, which provides a new opportunity for discovering and identifying novel effective treatment strategies.

Heterologous expression and characterization of Klebsiella oxytoca lysine decarboxylase / 生物工程学报

Cadaverine is a biogenic amine that has the potential to become an important platform chemical for the production of industrial polymers, such as polyamides and polyurethanes. We reported here a lysine decarboxylase from Klebsiella oxytoca. The lysine decarboxylase from Klebsiella oxytoca was cloned to Escherichia coli to get the strain LN18. The specific activity of the crude protein from LN18 reached 30 000 U. The molecular weight was about 80 kDa. The optimum temperature and pH of the crude protein were 55 ℃ and 5.5 respectively. The specific activity could keep over 30% at pH 8.0 compared the one at pH 5.5, much difference from Escherichia coli lysine decarboxylase CadA. Mg²⁺ was positive to the specific activity, whereas Fe²⁺, Zn²⁺ and Ca²⁺ were negative.

Cloning, prokaryotic expression and characterization of lysine decarboxylase gene from Huperzia serrata / 生物工程学报

Huperzine A is a promising drug to treat Alzheimer's disease (AD). To date, its biosynthetic pathway is still unknown. Lysine decarboxylase (LDC) has been proposed to catalyze the first-step of the biosynthesis of huperzine A. To identify and characterize LDCs from Huperzia serrata, we isolated two LDC fragments (LDC1 and LDC2) from leaves of H. serrata by RT-PCR and then cloned them into pMD 19-T vector. Sequence analysis showed that LDC1 and LDC2 genes shared 95.3% identity and encoded the protein of 212 and 202 amino acid residues respectively. Thus, we ligated LDC genes into pET-32a(+) to obtain recombinant expressing vectors pET-32a(+)/LDC1 and pET-32a(+)/LDC2 respectively. We further introduced two expression vectors into Escherichia coli BL21(DE3) and cultured positive colonies of E. coli in liquid LB medium. After inducing for 4 hours with 260 μg/mL IPTG at 30 degrees C, soluble recombinant Trx-LDC1 and Trx-LDC2 were obtained and isolated for purification using a Ni-NTA affinity chromatography. We incubated purified recombinant proteins with L-lysine in the enzyme reaction buffer at 37 degrees C and then derived the reaction products using dansyl chloride. It was found that both Trx-LDC1 and Trx-LDC2 had decarboxylase activity, could convert L-lysine into cadaverine by way of thin layer chromatography assay. Further, bioinformatics analysis indicated that deduced LDC1 and LDC2 had different physicochemical properties, but similar secondary and three-dimensional structures.

Effects of knockout of 2,3-butanediol synthesis key enzyme genes on 1,3-propandediol production in Klebsiella pneumoniae / 生物工程学报

2,3-butanediol (2,3-BD) is a major byproduct of 1,3-propandediol (1,3-PDO) fermentation by Klebsiella pneumoniae. To decrease the formation of 2,3-BD, the budC and budA gene, coding two key enzymes of 2,3-BD synthetic pathway in K. pneumoniae, were knocked out using Red recombination technology. The growth of the two mutants were suppressed in different level. The budC deficient strain fermentation results showed that 1,3-PDO concentration increased to 110% and 2,3-butanediol concentration dropped to 70% of the parent strain. However, the budA deficient strain did not produce 1,3-PDO and 2,3-BD, and the final titer of lactic acid, succinic acid, ethanol and acetic acid increased remarkably compared with the parent strain. Further analysis of budC deficient strain fermentation inferred that K. pneumoniae possessed the 2,3-BD cycle as a replenishment pathway. The consequence provided a new evidence for reforming low-byproduct K. pneumoniae.

Overexpression of Human Arginine Decarboxylase Rescues Human Mesenchymal Stem Cells against H2O2 Toxicity through Cell Survival Protein Activation

In this study, we explored the potentiality of human arginine decarboxylase (ADC) to enhance the survival of mesenchymal stem cells (MSCs) against unfavorable milieu of host tissues as the low survival of MSCs is the issue in cell transplantation therapy. To address this, human MSCs overexpressing human ADC were treated with H2O2 and the resultant intracellular events were examined. First, we examined whether human ADC is overexpressed in human MSCs. Then, we investigated cell survival or death related events. We found that the overexpression of human ADC increases formazan production and reduces caspase 3 activation and the numbers of FITC, hoechst, or propidium iodide positive cells in human MSCs exposed to H2O2. To elucidate the factors underlying these phenomena, AKT, CREB, and BDNF were examined. We found that the overexpression of human ADC phosphorylates AKT and CREB and increases BDNF level in human MSCs exposed to H2O2. The changes of these proteins are possibly relevant to the elevation of agmatine. Collectively, our data demonstrate that the overexpression of human ADC stimulates pro-survival factors to protect human MSCs against H2O2 toxicity. In conclusion, the present findings support that ADC can enhance the survival of MSCs against hostile environment of host tissues.

Cinnamic acid, ethanol and temperature interaction on coumarate decarboxylase activity and the relative expression of the putative cd gene in D. bruxellensis

Dekkera bruxellensis is one of the main contaminating yeasts in wine due to its ability to metabolize cinnamic acids into volatile phenols. This yeast metabolizes p-coumaric acid into 4-vinylphenol through a coumarate decarboxylase (CD) and then transforms it into to 4-ethylphenol (EF) through a vinylphenol reductase. In this work we investigated the influence of the interaction between the concentration of p-coumaric acid, ferulic acid and ethanol as well as growth temperature on the production of CD activity and the expression of a putative gene that codes for this enzymatic activity. For this, a Box Behnken experimental design was used. The concentration of p-coumaric acid (5-26 ppm) and ferulic acid (3-9 ppm) alone did not show any significant effect on any of the studied response variables. However, the interaction between (ethanol concentration * cinnamic acid concentration) and (ethanol concentration * temperature) had a significant statistical effect on the production of CD activity. Additionally, a higher growth temperature negatively affected the expression of the putative cd gene and the production of CD activity. This is the first work that studies the effect of cinnamic acids on the production of CD activity and the relative expression of its putative gene, using natural concentrations of cinnamic acid found in wine.

Surfactant protein A (SP-A) binds to phosphatidylserine and competes with annexin V binding on late apoptotic cells

The role of surfactant protein A (SP-A) in the recognition and clearance of apoptotic cells is well established, but to date, it is still not clear which surface molecules of apoptotic cells are involved in the process. Here we present evidence that phosphatidylserine (PS) is a relevant binding molecule for human SP-A. The binding is Ca(2+)-dependent and is not inhibited by mannose, suggesting that the sugar-binding site of the carbohydrate recognition domain (CRD) of SP-A is not involved. Flow cytometry studies on apoptotic Jurkat cells revealed apparent inhibition of annexin V binding by increasing concentrations of SP-A in late apoptotic but not early apoptotic cells, and this was consistent for Jurkat cells and neutrophils. Supporting these data, confocal microscopy results show a co-localisation of annexin V and SP-A in late apoptotic but not early apoptotic cells. However, we cannot conclude that this inhibition is exclusively due to the binding of SP-A to PS on the cell surface, as annexin V is not wholly specific for PS and SP-A also interacts with other phospholipids that might become exposed on the apoptotic cell surface.

Regulation of endothelial nitric oxide synthase by agmatine after transient global cerebral ischemia in rat brain / 대한해부학회지

Nitric oxide (NO) production by endothelial nitric oxide synthase (eNOS) plays a protective role in cerebral ischemia by maintaining vascular permeability, whereas NO derived from neuronal and inducible NOS is neurotoxic and can participate in neuronal damage occurring in ischemia. Matrix metalloproteinases (MMPs) are up-regulated by ischemic injury and degrade the basement membrane if brain vessels to promote cell death and tissue injury. We previously reported that agmatine, synthesized from L-arginine by arginine decarboxylase (ADC) which is expressed in endothelial cells, has shown a direct increased eNOS expression and decreased MMPs expression in bEnd3 cells. But, there are few reports about the regulation of eNOS by agmatine in ischemic animal model. In the present study, we examined the expression of eNOS and MMPs by agmatine treatment after transient global ischemia in vivo. Global ischemia was induced with four vessel occlusion (4-VO) and agmatine (100 mg/kg) was administered intraperitoneally at the onset of reperfusion. The animals were euthanized at 6 and 24 hours after global ischemia and prepared for other analysis. Global ischemia led severe neuronal damage in the rat hippocampus and cerebral cortex, but agmatine treatment protected neurons from ischemic injury. Moreover, the level and expression of eNOS was increased by agmatine treatment, whereas inducible NOS (iNOS) and MMP-9 protein expressions were decreased in the brain. These results suggest that agmatine protects microvessels in the brain by activation eNOS as well as reduces extracellular matrix degradation during the early phase of ischemic insult.

Agmatine Attenuates Nitric Oxide Synthesis and Protects ER-structure from Global Cerebral Ischemia in Rats / 대한해부학회지

In ischemic strokes, apoptosis is caused by excitotoxicity, ionic imbalance, oxidative/nitrosative stress, and apoptotic-like pathways. Nitric oxide (NO), a free radical, is elevated after ischemic insult. NO, which is generated primarily by neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS), promotes neuronal damage following ischemia. Evidence obtained in recent years has demonstrated that endoplasmic reticulum (ER)-mediated cell death plays an important role in cerebral ischemia. Agmatine is an endogenous substance synthesized from L-arginine by arginine decarboxylase (ADC) and is present in mammalian brain. We had previously reported that agmatine contributes to neuroprotection against ischemic injury. In continuation of our earlier work, we intended to investigate whether agmatine protects brain from transient global ischemia, and also tried to determine the neuroprotective mechanism of agmatine. Twenty minutes of transient global ischemia was induced by 4 vessel occlusion (4-VO). Agmatine (100 mg/kg, IP) was administered simultaneously with reperfusion. Samplings of brain were done at 6, 24, 48, and 72 h after reperfusion to determine the effect of agmatine on ischemic injured hippocampus. ER-damage was also investigated using electron microscope. Results showed that agmatine treatment prevented delayed neuronal cell death in hippocampal CA1 neurons after global cerebral ischemia. It also blocked NOS expression in the rat brain. Agmatine induced the increased expression of glucose-regulated protein 78 (Grp78). These results suggest that agmatine inhibits the production of NO by decreasing the expression of nNOS and iNOS on global forebrain ischemia and the neuroprotective effect of agmatine were concerned with the ER stress-mediated condition.

Development of Yvrk Gene-Recombinant E. coli Degrading Oxalate

PURPOSE: Recently, the whole DNA sequence of Bacillus subtilis (B. subtilis) was identified, revealing the existence of the YvrK gene encoding a 43 kD oxalate decarboxylase (OXDC), which degrades oxalate by a simple pathway. The objective of this study was to develop recombinant Escherichia coli (E. coli) expressing the Yvrk gene from B. subtilis. MATERIALS AND METHODS: After the extraction of total DNA from B. subtilis, the YvrK gene was cloned by polymerase chain reaction. The cloned DNA encoding OXDC was inserted into the pBAD/gIII-A vector, downstream of the L-arabinose promotor. The plasmid vector was transformed into TOP 10 E. coli, and the transformants were selected with ampicillin. The recombinant E. coli, named pBy, was then analyzed by DNA sequencing and Western blot. To evaluate the oxalate-degrading function of pBy, pBy was cultured in LB broth containing oxalate, and then the amount of oxalate in the medium was assessed. The oxalate-degrading activity of homogenates of pBy was evaluated. RESULTS: DNA sequencing showed the successful transformation of the YvrK gene into TOP 10 E. coli. Western blot analyses showed that pBy expressed OXDC. pBy removed oxalate during the overnight culture in oxalate-containing LB broth, and the homogenate of pBy degraded 90% of oxalate under acidic conditions. CONCLUSIONS: A recombinant E. coli expressing the YvrK gene was successfully produced. The bacteria showed potent oxalate-degrading activity. The results of this study will provide a solution to the treatment of calcium oxalate stones and hyperoxaluria, for which there are few medical treatment modalities.

Changes in free polyamines and related enzymes during stipule and pod wall development in Pisum sativum.

Level of free polyamines, their key metabolic enzymes, and other features related to ageing were examined during stipule and pod wall development in pea (Pisum sativum). Free polyamine titre (per unit fresh mass) in both the organs, the specific activities of arginine decarboxylase and ornithine decarboxylase in the pod wall, gradually decreased with maturation. In stipule, these enzymes attained peak activity at 15 days after pod emergence and declined thereafter. Ornithine decarboxylase activity was greater in pod wall than in stipule; while, arginine decarboxylase activity was higher in stipule. Activity of degradative enzyme diamine oxidase increased with the onset of senescence in both the organs. Chlorophyll and electrical conductance had a inverse relationship throughout the experimental period, whereas, the chlorophyll content was directly related with polyamine levels in both stipule and pod wall during aging. On the other hand, protein and RNA contents were positively correlated with free polyamines throughout the test period in stipule, but in the pod wall this was true only for the later stages of development.

An observation of taurine transport alterations in calcification of myocardial cells in vitro / 中国医学科学院学报

<p><b>OBJECTIVE</b>To observe the alterations of taurine transport, taurine transporter (TAUT) and cysteine sulfinate decarboxylase (CSD) mRNA in the calcification of myocardial cells in vitro.</p><p><b>METHODS</b>3H-taurine measured the amount of taurine uptake. TAUT and CSD mRNA consents were measured using competitive quantitative RT-PCR in cultured and calcified myocardial cells.</p><p><b>RESULTS</b>In calcification of myocardial cells, taurine concentration was decreased by 27% (P < 0.05), taurine uptake was markedly reduced, Vmax reduced by 39% (P < 0.01), there were no statistical significance of Km values between the two groups. TAUT mRNA decreased by 45% (P < 0.01), but CSD mRNA increased by 25% (P < 0.05).</p><p><b>CONCLUSIONS</b>The data suggest that there were impediment of taurine transport in calcification of myocardial cells, as TAUT mRNA level was decreased, but CSD mRNA concentration was improved.</p>

Importancia del metabolismo de la biotina / Importance of biotin metabolism

La biotina pertenece al grupo de las vitaminas hidrosolubles del complejo B. En humanos la biotina está directamente involucrada en importantes procesos metabólicos como la gluconeogénesis, la síntesis de ácidos grasos y el catabolismo de algunos aminoácidos, debido a su papel como grupo prostético de las enzimas piruvato carboxilasa, propionil-CoA carboxilasa, b-metilcrotonil-CoA carboxilasa y de la acetil-CoA carboxilasa. La biotina se une al sitio activo de estas enzimas y funciona como acarreador de CO2. Las carboxilasas se sintetizan como apocarboxilasas, carentes de biotina y la forma activa se produce por la unión covalente de la biotina al grupo e-amino de un residuo de lisina de la apocarboxilasa, reacción catalizada por la holocarboxilasa sintetasa. El paso final de la degradación de las carboxilasas es el rompimiento de la fracción biotinil del grupo e-amino de la lisina que es catalizada por la biotinidasa y resulta en la liberación de la biotina libre, la cual puede ser nuevamente reciclada. La biotina regula, a nivel postranscripcional, la expresión de la propionil-CoA carboxilasa y, a nivel transcripcional, a la de la holocarboxilasa sintetasa. Además de su papel como cofactor y regulador de la biosíntesis de las carboxilasas, la biotina está involucrada en otras áreas del metabolismo, donde regula la síntesis de proteínas específicas entre las que se encuentran el receptor de la asialoglicoproteína, varias enzimas reguladoras del metabolismo de glucosa y proteínas que unen biotina en la yema de huevo, entre otras. La deficiencia de biotina se ha reportado en pacientes sometidos a una alimentación parenteral total, en personas que ingieren grandes cantidades de clara de huevo crudo, en niños con desnutrición energético proteínica severa y en personas con errores innatos del metabolismo. Entre estas últimas se encuentran las enfermedades autosómicas recesivas del metabolismo de biotina que resultan de la alteración de la actividad de la holocarboxilasa sintetasa o de la biotinidasa.

[Insulin dependent diabetes mellitus and antibodies to glutamic acid decarboxylase]

Insulin dependent diabetes mellitus [IDDM] is an autoimmune disease, the factors that induce the selective destruction of the insulin producing islet cells of the pancreas are unknown. Although autoreactive T-cells rather than autoantibodies are responsible for the destruction of beta-cells, the identification and chararcterization of the autoantibody-autoantigen system in IDOM are of crucial and fundamental importance in prediction and potential immunotherapy of the disease. Currently, Cytoplasmic Islets Cell Antibodies [ICAs Insulin Autoantibodies [IAA], Glutamic Acid Decarboxylase Antibodies [Anti-GADs] and 37-k antigen antibodies are potentially useful hurnoral markers for such prediction. The attempt to identify the earliest events in the autoimmune process suggest that Anti-GAD could be the first and most important autoantigen

Immunologic prevention of IDDM by oral administration of glutamic acid decarboxylase

We have investigated the preventive effects of oral administration of isolated E.coli glutamic acid decarboxylase [GAD] in animal models. Based on our results, the blood glucose levels were reduced by oral administration of GAD to rats 14 days before intraperitoneal injections of streptozocin [40 mg/kg on five consecutive days]. On the other hand, oral administration of GAD to rats before streptozocin treatment significantly [P< 0.05] reduced the levels of GAD - specific antibodies and improved the in vitro proliferative responses of splenocytes to Con A. These data demonstrate that oral GAD administration probably generates active cellular mechanisms that suppress the disease and raise the possibility of using E.coli GAD as a new means for the prevention of autoimmune diabetes

Estudo de prevalência em recém-nascidos por deficiência de biotinidase / Neonatal screening for biotinidase deficiency

A deficiência de biotinidase é um erro inato do metabolismo caracterizado principalmente por ataxia, crise convulsiva , retardo mental, dermatites, alopécia e susceptibilidade a infecçöes. É atribuída a esta deficiência enzimática a forma tardia de deficiência múltipla das carboxilases. Com o objetivo de verificar a prevalência da deficiência de biotinidase e validar o teste de triagem neonatal considerando a relaçäo custo/benefício, elaborou-se estudo prospectivo na populaçäo de recém-nascidos no Estado do Paraná. Em um período de 8 meses foram triados 125.000 recém-nascidos. A amostra sangüínea foi a mesma obtida para os testes de triagem para fenilcetonúria e hipotireoidismo congênito, submetida ao teste semiquantitativo colorimétrico para atividade de biotinidase. As amostras consideradas suspeitas foram repetidas em duplicatas do mesmo cartäo de papel de filtro, e as que permaneceram alteradas solicitou-se novo cartäo. O teste quantitativo colorimétrico da doença foi realizado nos casos em que a segunda amostra testada em duplicata sugeriu deficiência de biotinidase. A taxa de repetiçäo em duplicata variou de 0,9 por cento a 0,5 por cento do total de exames realizados por mês. A taxa de reconvocaçäo do segundo cartäo foi de 0,17 por cento, sendo que destes 212 casos, 30 por cento näo retornaram o segundo cartäo solicitado. Foram identificados 2 casos, um de deficiência total de biotinidase e outro foi de 1:62.500 nascidos-vivos. A sensibilidade do teste semiquantativo colorimétrico foi calculada em 100 por cento e a especificidade 99,88 por cento. A prevalência da doença no Estado do Paraná foi de 1:125.000 nascidos-vivos para deficiência total de enzima, levando-se em consideraçäo que 30 por cento de casos suspeitos que repetiram novo teste. O teste semiquantativo colorimétrico foi considerado efetivo em identificar os casos afetados, com sensibilidade de 100 por cento especificidade de 99,88 por cento. A relaçäo custo/benefício foi satisfatória, permitindo a inclusäo do teste de detecçäo de deficiência de biotinidase no programa de triagem neonatal do Estado do Paraná

Efecto de la cocarboxilasa no degradable en la acidosis metabólica del neonato de término con asfixia perinatal / Effects of non degradable cocorboxilase and metabolic acidosis in term neonate with perinatal asphyxia

Antecedentes. La Cocarboxilasa No Degradable (CND); coenzima de la deshidrogenasa pirúvica, en la mitocondria, puede ejercer sus efectos benéficos en la normalización de pH y mantenimiento de la reserva alcalina, ya en un estudio anterior se demostró que no existían diferencias significativas al compararlo con bicarbonato. Objetivo. Demostrar que la CND revierte la acidosis metabólica relacionada a asfixia al nacimiento en recién nacidos de término eutróficos sin otra patología asociada. Material y método. En un estudio, realizado de julio de 1993 a julio de 1994, se estudiaron 10 recién nacidos, de término, eutróficos con Apgar igual o menor a 3 y con alteraciones acidobásicas demostradas mediante gasometrías. Se administra un total de 3 CND con materiales de 8 horas a razón de 80 mg/kg, determinandose gasometrías 15 minutos después de la administración, las variables consideradas fueron: pH, PCO2, PO2 y bicarbonato, exceso de base, tensión arterial media, frecuencia cardiaca, temperatura y hematocrito. Resultados. El peso fué de 3236ñ511.7 g, con una edad gestaciones de 40ñ1 semanas. En las gasometrías: el pH promedio basal fué 7.14ñ0.06, apreciandose corrección desde la 1a. muestra después de la administración de CND con 7.36ñ0.07. El exceso de base basal fué de -10.6ñ3.6 y también se encontrarón diferencias en las siguientes determinaciones. El mismo comportamiento se aprecia en la PCO2. Para la PO2 y HCO3 los resultados no presentaron diferencias demostrables en forma individual o tendencias significativas en el comportamiento grupal. Conclusiones. Se apreció correción en la acidosis 15 minutos después del uso de la CND, corrigiendo pH, HCO3 y Exceso de Base desde la primera administración. Corroborando lo expuesto en el primer estudio de este trabajo el efecto de la CND se hace patente al duplicar la dosis

Complicaciones motoras precoces en parkisonianos de novo tratados con L-Dopa más inhibidor periférico de la decarboxilasa / Early motor complications in parkisonians of novo treated with L-Dopa plus descarboxylase inhibitor

En una serie de 27 pacientes con enfermedad de Parkinson esencial de novo, en grado 2,7 de Hoehn y Yahr como promedio, con un rango de 1 a 4, tratados con levodopa más benserazida durante 16 semanas, se observaron efectos motores adversos leves a moderados en 12 casos (44,4 por ciento): 8 pacientes presentaron diskinesias, 7 distonías y un deterioro de final de dosis. La dosis máxima de levodopa ID utilizada fue de 750 mg los que alcanzaron a la tercera semana, previo ascenso paulatino desde 125 mg inicial. Posteriormente, se buscó la mínima dosis efectiva la cual correspondió a una cifra de 475 mg como media con un rango de 250 a 750 mg correspondiente a 49,7 por ciento de reducción, lográndose un efecto antiparkinsoniano similar al obtenido con la dosis máxima. Se discuten los posibles factores que hayan influido en el porcentaje alto de efectos motores adversos encontrados en esta serie