Antibodies & immunoassays for small molecules Amino acids in brain health & disease: why and how to measure them easily ?
Amino acids are critical for brain function. They serve as building blocks for neurotransmitter and protein synthesis, supply energy, detoxify ammonia, modulate synaptic function, and regulate gene expression. Measuring amino acids and their byproducts in blood, urine, or CSF is therefore critical for assessing neurodegenerative diseases, psychiatric disorders, brain tumors, traumatic injury, stroke, as well as rare neurological diseases.
Over the past 10 years, our team at Immusmol has developed a range of ELISA kits enabling easy quantification of amino acids in research samples. Highly accurate and specific, our ELISA kits have been cross-validated by LC-MS (data available for each kit). In addition, our team has validated a range of primary antibodies for their visualization in cell cultures, tissue sections, and whole mounts.
Here, we provide a quick overview of the role of key amino acids in brain health and disease, and how our tools can help scientists in their detection:
Role in Neurobiology
Nitric Oxide (NO) production: precursor for nitric oxide (NO), a critical neurotransmitter and vasodilatator, influencing cerebral blood flow, synaptic plasticity, learning, and memory
Polyamine synthesis (putrescine, spermidine, spermine): regulating neural growth & differentiation
Brain pathologies
Neurodegenerative diseases: dysregulated NO leads to oxidative stress in Alzheimer’s and Parkinson’s
Stroke: excessive NO exacerbates neuronal damage during ischemia
Urea cycle disorders: elevated levels or metabolic deficiencies in arginine metabolites (Citrullinemia, Ornithine Transcarbamylase Deficiency) lead to hyperammonemia, causing lethargy, seizures, and cognitive impairment
Brain tumors: excess of NO and polyamines often correlates with brain tumor malignancy (angiogenesis, aggressiveness, resistance to therapies)
Research & diagnostics interest
Oxidative stress levels in the context of neurological conditions: Arginine, Citrulline, Ornithine plasma & CSF levels
Urea cycle disorders: plasma & urine concentrations of citrulline, homoarginine, ornithine
Cerebrovascular risk: arginine & homoarginine plasma levels
Brain tumors: arginine and its metabolites in CSF and plasma
Associated products
Amino acids ELISAs: Arginine ELISA kit, Ornithine ELISA kit, Citrulline ELISA kit, HomoArginine ELISA kit
Polyamines ELISAs: N1-Acetyl-Spermidine ELISA kit, N8-Acetyl-Spermidine ELISA kit
Ratios ELISA packs: Arginine-to-Ornithine ratio ELISA pack, Citrulline-to-Arginine ratio, Global Arginine Bioavailability ratio (GABR) ELISA pack
Role in Neurobiology
Protein synthesis: vital for asparagine-linked glycosylation affecting neural proteins
Neurotransmitter regulation: modulates release and synaptic function
Brain pathologies
Asparagine synthetase deficiency: Leads to severe neurodevelopmental delays and epilepsy
Cancer metabolism: Altered levels might affect tumor growth in brain cancers
Research & diagnostics interest
Brain tumor metabolism asparagine levels in plasma or CSF
Neurodegenerative diseases: neurotransmitter amino acid levels in CSF
Associated products
Role in Neurobiology
Primary excitatory neurotransmitter: essential for synaptic transmission.
Synaptic plasticity: crucial for learning and memory formation.
Brain pathologies
Excitotoxicity: Excess leads to neuronal damage in stroke, TBI, ALS, epilepsy.
Mood disorders: altered glutamatergic system in bipolar and major depressive disorders
Brain tumors: secreted by tumors, promoting tumor invasion
Research & diagnostics interest
Stroke, Traumatic brain injury, ALS, Epilepsy: glutamate concentrations in CSF to assess excitotoxic damage.
Mood disorders: glutamate & glutamine levels in serum, CSF and brain tissues
Brain tumors: glutamate concentrations in plasma & CSF
Associated products
ELISA kits: Glutamate ELISA kit, Glutamine ELISA Kit
Primary antibodies: D-Glutamate Antibody, L-Glutamate Antibody (Mouse mAb), L-Glutamate Antibody (rabbit pAb)
Role in Neurobiology
Glutamate precursor: converted to glutamate in neurons
Glutamine-Glutamate Cycle: shuttles between neurons and astrocytes to maintain glutamate & GABA pools
Brain pathologies
Hepatic Encephalopathy: elevated brain glutamine causes cerebral edema and cognitive impairment
Mood disorders: altered glutamate-glutamine function is associated with depression, anxiety, and schizophrenia
Brain tumor metabolism: glutamine serves as key nutrient, contributing to tumor growth, survival & aggressiveness
Research & diagnostics interest
Hepatic Encephalopathy: detection of high glutamine levels in plasma
Mood disorders: measurement of glutamine, glutamate & GABA in plasma, CSF, and brain tissues
Biomarker of aggressive tumors: glutamine levels in CSF & plasma
Associated products
ELISA kits: Glutamine ELISA kit, GABA ELISA kit, Glutamate ELISA kit
Primary antibody: Glutamine antibody, Gaba antibodies, Glutamate antibodies
Role in Neurobiology
Inhibitory neurotransmitter: glycine mediates inhibitory transmission in the spinal cord and brainstem.
NMDA receptor co-agonist: it binds to NMDA receptors, facilitating excitatory neurotransmission and synaptic plasticity.
Brain pathologies
Glycine encephalopathy (Nonketotic Hyperglycinemia): genetic disorder causing glycine accumulation, leading to seizures, hypotonia, and developmental delay.
Hyperekplexia: mutations in glycine receptors result in exaggerated startle responses and muscle stiffness
Psychiatric disorders: Glycine modulates NMDA receptors, affecting mood, and is a ligand of the newly-discovered metabotropic glycine receptor (mGlyR) involved in stress-induced depression
Brain tumors: aggressive tumors consume and synthesize glycine to proliferate and escape immune control
Research & diagnostics interest
Nonketotic Hyperglycinemia (NKH): measurement CSF and plasma glycine levels
Schizophrenia & mood disorders: glycine CSF and plasma levels can be measured to assess antidepressant effects
Biomarker of aggressive tumor: glycine is marker of high-grade gliomas
Associated products
Role in Neurobiology
Histamine synthesis: precursor to histamine involved in wakefulness, appetite, and cognition.
Myelin sheath formation: supports neuron insulation.
Brain pathologies
Sleep disorders: Altered histamine levels affect sleep cycles (e.g., narcolepsy).
Cognitive dysfunction: histidine deficit in attention deficits and Alzheimer’s.
Brain tumors: glioblastoma stem cells use histidine to produce and secrete histamine to remodel the tumor microenvironment
Research & diagnostics interest
Sleep disorders: histamine levels in CSF
Attention deficit disorders: plasma histidine levels
Brain tumors histidine in CSF & histamine levels in CSF & plasma
Associated products
ELISA kits: Histidine ELISA, Histamine ELISA
Primary antibodies: Histidine antibody, Histamine antibody
Role in Neurobiology
Protein synthesis: Essential for proteins production
Epigenetic Regulation: Lysine residues on histones influence gene expression (methylation, acetylation).
Brain pathologies
Lysine deficiency: insufficient levels of Lysine impair neurotransmitter release and cognition.
Glutaric Acidemia Type I: excess of lysine cause neural damage
Brain tumors: glioblastoma stem cells remodel lysine catabolism to repress IFN signaling
Research & diagnostics interest
Insufficiency dietary Lysine uptake: plasma levels of Lysine
Brain tumors: plasma levels & CSF level of Lysine
Associated products
ELISA kit: L-Lysine ELISA
Primary antibody: L-Lysine antibody
Role in Neurobiology
Catecholamine production: essential for the production of neurotransmitters dopamine, norepinephrine, and epinephrine, influencing motor control, cognition, mood and stress response
Brain pathologies
Phenylketonuria (PKU): L-Phenylalanine accumulation is neurotoxic, disrupting neurotransmitter synthesis and causing neural damage
Tyrosine Hydroxylase Deficiency: causes impaired catecholamine synthesis, leading to motor delays and developmental issues.
Parkinson’s Disease: characterized by dopamine deficiency due to loss of dopaminergic neurons.
Research & diagnostics interest
Dietary Monitoring: phenylalanine levels in plasma
Catecholamines in plasma & CSF: relevant for the assessment and diagnosis of a large array for neurological conditions, such as neuroblastoma, movement disorders, psychiatric diseases, neurodegenerative diseases, cerebrovascular disorders, and drug abuse.
Associated products
ELISA kits: L-Phenylalanine ELISA, Catecholamines ELISAs
Primary antibodies: L-Phenylalanine antibody, L-Tyrosine antibody, L-Dopamine antibody, Norepinephrine antibody, L-Dopa antibody, 3-MT antibody
Role in Neurobiology
Protein synthesis: essential for the production of proteins, incorporated into polypeptide chains during translation
Precursor to D-Serine & Glycine: Converted by serine racemase, influencing NMDA receptor activity.
Precursor to Sphingolipids & Phospholipids : essential for myelin sheath formation and neuronal membrane integrity.
Neuroprotection and glial cell proliferation
Brain pathologies
Serine Deficiency Disorders: Leads to severe neurological impairment, including seizures and developmental delays.
Neurodegenerative diseases: L-serine has a neuroprotective activity
Brain tumors: Serine promotes the survival of glioblastoma cells in hypoxic conditions (one-carbon metabolism)
Research & diagnostics interest
Serine deficiency: plasma levels of L-Serine to assess dietary supplementation
L-Serine imaging to investigate pathogenesis and potential therapeutic strategies in neurodegeneration and neuro-oncology.
Associated products
ELISA kit: L-Serine ELISA
Primary antibody: L-Serine antibody, D-Serine antibody, Glycine Antibody
Role in Neurobiology
Co-agonist at NMDA receptors aiding glutamatergic neurotransmission and synaptic plasticity.
Regulation by astrocytes D-Serine is synthesized and released by astrocytes
Brain pathologies
Schizophrenia: low D-serine levels linked to NMDA receptor hypofunction.
Alzheimer’s Disease: Neurotoxic effects of D-serine metabolism dysregulation (NMDA receptor-mediated excitotoxicity)
ALS: involved in motor neuron degeneration through excitotoxicity
Research & diagnostics interest
Biomarker of Schizophrenia: reduced D-serine serum & CSF levels
Monitoring of therapies targeting NMDA receptors
ALS: D-serine plasma & CSF levels
Associated products
Role in Neurobiology
Protein synthesis: essential for the production of proteins, incorporated into polypeptide chains during translation
Precursor to D-Serine & Glycine: Converted by serine racemase, influencing NMDA receptor activity.
Precursor to Sphingolipids & Phospholipids : essential for myelin sheath formation and neuronal membrane integrity.
Neuroprotection and glial cell proliferation
Brain pathologies
Serine Deficiency Disorders: Leads to severe neurological impairment, including seizures and developmental delays.
Neurodegenerative diseases: L-serine has a neuroprotective activity
Brain tumors: Serine promotes the survival of glioblastoma cells in hypoxic conditions (one-carbon metabolism)
Research & diagnostics interest
Serine deficiency: plasma levels of L-Serine to assess dietary supplementation
L-Serine imaging to investigate pathogenesis and potential therapeutic strategies in neurodegeneration and neuro-oncology.
Associated products
ELISA kit: L-Serine ELISA
Primary antibody: L-Serine antibody, D-Serine antibody, Glycine Antibody
Role in Neurobiology
Serotonin & melatonin precursor: regulates mood, sleep, and appetite.
Precursor of kynurenines: regulating neuroimmune function, the kynurenine pathway includes neuroprotective kynurenic acid and neurotoxic Quinolinic acid
Brain pathologies
Inflammatory neurological disorders: upregulation of tryptophan catabolism along the kynurenine pathway and reduced serotonin synthesis are observed in depression, anxiety, schizophrenia, neurodegenerative disease, multiple sclerosis, autism, chronic fatigue.
Sleep disorders, Eating Disorders, Migraine, Bipolar disorders involve dysregulated or fluctuating serotonin synthesis
Brain tumors: serotonin promotes glioblastoma growth, migration and angiogenesis. Kynurenine overproduction promote immune tolerance and promote tumor growth (while quinolinic acid exacerbates neural damage)
Research & diagnostics interest
Neuroinflammatory disorders: high kynurenine to tryptophan ratio in plasma & CSF, assessment of concentrations of quinolinic & kynurenic acids, serotonin & melatonin levels
Disorders related to serotonin deficiency / dysregulation: low serotonin levels and 5-HIAA levels in CSF or plasma
Sleep disorders: low melatonin levels in plasma
Brain tumors: Tryptophan to kynurenine ratio and serotonin levels in CSF and plasma, and assessment of Quinolinic acid in CSF