Aminobutyrates ; Autoantibodies ; Child ; Encephalitis ; Humans

Leucine dehydrogenase (LDH) is the key rate-limiting enzyme in the production of L-2-aminobutyric acid (L-2-ABA). In this study, we modified the C-terminal Loop region of this enzyme to improve the specific enzyme activity and stability for efficient synthesis of L-2-ABA. Using molecular dynamics simulation of LDH, we analyzed the change of root mean square fluctuation (RMSF), rationally designed the Loop region with greatly fluctuated RMSF, and obtained a mutant EsLDHD2 with a specific enzyme activity 23.2% higher than that of the wild type. Since the rate of the threonine deaminase-catalyzed reaction converting L-threonine into 2-ketobutyrate was so fast, the multi-enzyme cascade catalysis system became unbalanced. Therefore, the LDH and the formate dehydrogenase were double copied in a new construct E. coli BL21/pACYCDuet-RM. Compared with E. coli BL21/pACYCDuet-RO, the molar conversion rate of L-2-ABA increased by 74.6%. The whole cell biotransformation conditions were optimized and the optimal pH, temperature and substrate concentration were 7.5, 35 °C and 80 g/L, respectively. Under these conditions, the molar conversion rate was higher than 99%. Finally, 80 g and 40 g L-threonine were consecutively fed into a 1 L reaction mixture under the optimal conversion conditions, producing 97.9 g L-2-ABA. Thus, this strategy provides a green and efficient synthesis of L-2-ABA, and has great industrial application potential.
Aminobutyrates ; Escherichia coli/genetics* ; Leucine Dehydrogenase/genetics* ; Threonine Dehydratase

Biballism is an infrequent hyperkinetic disorder characterized by always ceaseless, repetitive, complex, violent involuntary movement involving proximal muscles. Biballism is classically ascribed to ischemic stroke in the subthalamic nucleus or its connections but other causes (infection, toxin, systemic disease) have been reported. Potential pathogenic mechanism include relative dopamlnergic hypersensitivity associated with basal ganglia lesion, impaired synthesis of acetylcholine or aminobutyric acid or undefined effect of hyperosmolarity. We report a case of biballism occurred due to a infarction of left basal ganglia and nonketotic hyperglycemia.
Acetylcholine ; Aminobutyrates ; Basal Ganglia* ; Dyskinesias ; Humans ; Hyperglycemia ; Hypersensitivity ; Infarction ; Muscles ; Stroke ; Stroke, Lacunar* ; Subthalamic Nucleus

Biballism is an infrequent hyperkinetic disorder characterized by always ceaseless, repetitive, complex, violent involuntary movement involving proximal muscles. Biballism is classically ascribed to ischemic stroke in the subthalamic nucleus or its connections but other causes (infection, toxin, systemic disease) have been reported. Potential pathogenic mechanism include relative dopamlnergic hypersensitivity associated with basal ganglia lesion, impaired synthesis of acetylcholine or aminobutyric acid or undefined effect of hyperosmolarity. We report a case of biballism occurred due to a infarction of left basal ganglia and nonketotic hyperglycemia.
Acetylcholine ; Aminobutyrates ; Basal Ganglia* ; Dyskinesias ; Humans ; Hyperglycemia ; Hypersensitivity ; Infarction ; Muscles ; Stroke ; Stroke, Lacunar* ; Subthalamic Nucleus

In this study, Escherichia coli BL21 (DE3) was used as the host to construct 2 recombinant E. coli strains that co-expressed leucine dehydrogenase (LDH, Bacillus cereus)/formate dehydrogenase (FDH, Ancylobacter aquaticus), or leucine dehydrogenase (LDH, Bacillus cereus)/alcohol dehydrogenase (ADH, Rhodococcus), respectively. L-2-aminobutyric acid was then synthesized by L-threonine deaminase (L-TD) with LDH-FDH or LDH-ADH by coupling with two different NADH regeneration systems. LDH-FDH process and LDH-ADH process were optimized and compared with each other. The optimum reaction pH of LDH-FDH process was 7.5, and the optimum reaction temperature was 35 °C. After 28 h, the concentration of L-2-aminobutyric acid was 161.8 g/L with a yield of 97%, when adding L-threonine in batches for controlling 2-ketobutyric acid concentration less than 15 g/L and using 50 g/L ammonium formate, 0.3 g/L NAD+, 10% LDH-FDH crude enzyme solution (V/V) and 7 500 U/L L-TD. The optimum reaction pH of LDH-ADH process was 8.0, and the optimum reaction temperature was 35 °C. After 24 h, the concentration of L-2-aminobutyric acid was 119.6 g/L with a yield of 98%, when adding L-threonine and isopropanol (1.2 times of L-threonine) in batches for controlling 2-ketobutyric acid concentration less than 15 g/L, removing acetone in time and using 0.3 g/L NAD⁺, 10% LDH-ADH crude enzyme solution (V/V) and 7 500 U/L L-TD. The process and results used in this paper provide a reference for the industrialization of L-2-aminobutyric acid.
Aminobutyrates ; metabolism ; Escherichia coli ; genetics ; Formate Dehydrogenases ; metabolism ; Leucine Dehydrogenase ; metabolism ; NAD ; metabolism

Status epilepticus and hypotension are the main causes of death from glufosinate-surfactant herbicide (GluSH) poisoning. Affected patients do not respond to general treatment. We encountered a 57 year-old female patient admitted to the emergency department after GluSH poisoning. She did not show any abnormal signs except for a mild drowsy mental status at presentation. During conservative management and observation, convulsion and hypotension occurred. After mechanical ventilator care and anticonvulsant administration, the convulsion was controlled but the hypotension was refractory to fluid resuscitation and vasopressors. Twenty-two hours after hospital admission, intravenous fat emulsion (IFE) was attempted. After IFE, the mean arterial pressure increased to more than 65 mmHg, and the left ventricular ejection fraction improved from 30% to 50%, so the vasopressors could be tapered. The patient received additional treatment and was discharged without complications.
Aminobutyrates ; Arterial Pressure ; Cause of Death ; Emergencies ; Female ; Humans ; Hypotension ; Resuscitation ; Seizures ; Status Epilepticus ; Stroke Volume ; Ventilators, Mechanical

Aminobutyrates ; Angiotensin Receptor Antagonists ; China ; Consensus ; Drug Combinations ; Heart Failure/drug therapy* ; Humans ; Neprilysin ; Stroke Volume ; Tetrazoles ; Valsartan

Although glufosinate ammonium herbicides are considered safe when used properly, ingestion of the undiluted form can cause grave outcomes. Recently, we treated a 34-yr-old man who ingested glufosinate ammonium herbicide. In the course of treatment, the patient developed apnea, mental deterioration, and sixth cranial nerve palsy; he has since been discharged with full recovery after intensive care. This case report describes the clinical features of glufosinate intoxication with a focus on sixth cranial nerve palsy. Our observation suggests that neurologic manifestations after ingestion of a "low-grade toxicity herbicide" are variable and more complex than that was previously considered.
Abducens Nerve Diseases/*chemically induced/drug therapy ; Adult ; Aminobutyrates/*poisoning ; Enzyme Inhibitors/poisoning ; Herbicides/*poisoning ; Humans ; Male ; Seizures/chemically induced ; Surface-Active Agents/poisoning ; Unconsciousness/chemically induced

OBJECTIVETo examine the changes in the expression of mGluR4 after diffuse brain injury (DBI) and to determine the role of its specific agonist L-2-amino-4-phosphonobutyrate (L-AP4) in vivo.

METHODSA total of 161 male SD rats were randomized into the following groups. Group A included normal control, sham-operated control and DBI group. DBI was produced according to Marmarou's diffuse head injury model. mRNA expression of mGluR4 was detected by hybridization in situ. Group B included DBI alone, DBI treated with normal saline and DBI treated with L-AP4. All DBI rats were trained in a series of performance tests, following which they were subjected to DBI. At 1 and 12 hours, animals were injected intraventricularly with L-AP4 (100 mmol/L, 10 microl) or normal saline. Motor and cognitive performances were tested at 1, 3, 7, 14 days after injury and the damaged neurons were also detected.

RESULTSThere was no significant difference between normal control group and sham-operated group in the expression of mGluR4 (P>0.05). The animals exposed to DBI showed significantly increased expression of mRNA of mGluR4 compared with the sham-operated animals 1 h after injury (P<0.05). At 6 hours, the evolution of neuronal expression of mGluR4 in the trauma alone group was relatively static. Compared with saline-treated control animals, rats treated with L-AP4 showed an effective result of decreased number of damaged neurons and better motor and cognitive performances.

CONCLUSIONSIncreased expression of mGluR4 is important in the pathophysiological process of DBI and its specific agonist L-AP4 can provide remarkable neuroprotection against DBI not only at the histopathological level but also in the motor and cognitive performance.

Aminobutyrates ; pharmacology ; Analysis of Variance ; Animals ; Brain Injuries ; metabolism ; Excitatory Amino Acid Agonists ; pharmacology ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Metabotropic Glutamate ; drug effects ; metabolism

To identify metabotropic glutamate receptor 4 (mGluR4) modulators by Ca2+ influx assay, we developed the functional cell-based high throughput-screening (HTS) assay. The human mGluR4 cDNA was transfected into HEK-293 stably expressing promiscuous G-protein (Ga alpha15) cells. Recombinant stable mGluR4 cell line was selected under Zeocin and validated by Ca2+ influx assay. The assay was optimized on loading time of Fluo Calcium Indicator, Dimethyl sulfoxide (DMSO) tolerance and sodium hydroxide (NaOH) tolerance using agonist (L-Glutamic acid (L-Glu)) of mGluR4. The rank order of the agonist potency for the stable human mGluR4 cell line was L-(+)-2-Amino-4-phosphonobutyric acid (L-AP4) > L-Serine-O-phosphate (L-SOP) > L-Glu, and of the antagonist potency was (RS)-alpha-Methylserine-O-phosphate (MSOP) > (RS)-alpha-Methyl-4-phosphonophenylglycine (MPPG). Z' factor value of the cell line in 96- and 384-well plate format was 0.80 and 0.65. Our data indicate a successful development of functional human mGluR4 recombinant stable cell line that was suitable for high throughput screening to identify mGluR4 agonist/antagonist.
Aminobutyrates ; pharmacology ; Cell Line ; DNA, Complementary ; genetics ; Drug Evaluation, Preclinical ; Humans ; Kidney ; cytology ; embryology ; Phosphoserine ; pharmacology ; Plasmids ; genetics ; Receptors, Metabotropic Glutamate ; agonists ; antagonists & inhibitors ; genetics ; Transfection