Selank

Research Overview

Selank serves as a valuable research tool for investigating anxiolytic mechanisms, cognitive enhancement pathways, and immune system modulation in laboratory settings. This synthetic heptapeptide represents a structural analog of tuftsin (Thr-Lys-Pro-Arg), an endogenous immunomodulatory peptide cleaved from the Fc-fragment of immunoglobulin G. Research applications have expanded beyond immunological studies to encompass neuroscience, behavioral pharmacology, and stress response investigations across multiple experimental systems.

The peptide’s development involved extending the tuftsin sequence with a Gly-Pro-Pro C-terminal tail, which significantly enhances metabolic stability and biological half-life compared to the parent peptide. Laboratory studies investigate Selank’s effects on neurotransmitter systems, particularly GABAergic and monoaminergic pathways, stress-induced behavioral changes, and cognitive performance markers in preclinical models.

Selank research demonstrates the peptide’s unique pharmacological profile characterized by anxiolytic-like effects without sedation, cognitive enhancement without stimulant properties, and immunomodulatory activity. These characteristics make it a valuable tool for dissecting the relationships between stress response systems, immune function, and cognitive processes.

Molecular Characteristics

Complete Specifications:

• CAS Registry Number: 129954-34-3
• Molecular Weight: 751.87 Da
• Molecular Formula: C₃₃H₅₇N₁₁O₉
• Amino Acid Sequence: Thr-Lys-Pro-Arg-Pro-Gly-Pro
• Peptide Classification: Synthetic tuftsin analog
• Appearance: White to off-white lyophilized powder
• Solubility: Water, bacteriostatic water, phosphate buffered saline
• Net Charge: +2 at physiological pH

The peptide’s 7-amino acid structure incorporates three proline residues (positions 3, 5, and 7) that contribute to conformational stability and resistance to peptidase degradation. The N-terminal sequence (Thr-Lys-Pro-Arg) maintains the tuftsin immunomodulatory core, while the C-terminal extension (Pro-Gly-Pro) provides enhanced pharmacokinetic properties. The presence of basic residues (lysine, arginine) creates a net positive charge facilitating potential interactions with negatively charged cell membrane components.

Pharmacokinetic Profile in Research Models

Selank pharmacokinetic characterization in preclinical research reveals important properties for experimental design:

Absorption and Distribution:

• Intranasal bioavailability: Higher than parenteral routes in rodent models
• Blood-brain barrier penetration: Documented in experimental studies
• Peak plasma concentrations: 15-30 minutes post-administration
• Brain tissue distribution: Detected in multiple regions including cortex and hippocampus

Metabolism and Elimination:

• Plasma half-life: Approximately 20-30 minutes (extended vs. tuftsin)
• Metabolic stability: Resistant to rapid peptidase degradation
• Primary metabolism: Enzymatic cleavage at specific peptide bonds
• Biological effects: Observed for hours beyond detectable plasma presence

These pharmacokinetic characteristics inform research protocol design, particularly regarding administration routes, dosing intervals, and timing of behavioral or biochemical assessments in experimental models.

Research Applications

Anxiolytic Mechanism Studies

Selank serves as a research tool for investigating non-benzodiazepine anxiolytic mechanisms:

• GABAergic System Research: Investigation of GABA receptor modulation without direct agonism
• Stress Response Studies: Analysis of HPA axis regulation and cortisol modulation
• Behavioral Pharmacology: Examination of anxiety-like behaviors in validated animal models
• Neurotransmitter Balance: Studies on serotonin, dopamine, and norepinephrine system interactions
• Neural Circuit Investigation: Research on amygdala, prefrontal cortex, and hippocampal connectivity

Research protocols typically employ anxiety behavioral paradigms (elevated plus maze, open field test, social interaction test) combined with neurochemical analysis and electrophysiological recordings to characterize Selank’s anxiolytic mechanisms.

Cognitive Function Research

Laboratory studies investigate Selank in cognitive enhancement research:

• Memory Formation Studies: Investigation of encoding, consolidation, and retrieval processes
• Attention and Focus Research: Analysis of sustained attention and selective attention mechanisms
• Learning Paradigms: Studies examining acquisition rates and retention in various learning tasks
• Cognitive Flexibility: Research on task switching, reversal learning, and adaptive behavior
• Neuroplasticity Markers: Investigation of BDNF, synaptic protein expression, and dendritic spine density

Experimental models include Morris water maze, novel object recognition, fear conditioning, and operant conditioning paradigms, with outcomes measured through behavioral performance, molecular markers, and electrophysiological correlates.

Neuroprotection Research Applications

Research applications extend to neuroprotective mechanism investigation:

• Oxidative Stress Studies: Examination of antioxidant enzyme expression and ROS modulation
• Neuroinflammation Research: Investigation of microglial activation and cytokine production
• Excitotoxicity Models: Studies on glutamate-induced neurotoxicity protection mechanisms
• Apoptotic Pathway Analysis: Research on caspase activation and cell survival signaling
• Neurotrophic Factor Modulation: Investigation of BDNF, NGF, and related growth factor expression

Laboratory protocols investigate Selank’s neuroprotective effects in cell culture models (primary neurons, neuronal cell lines) and in vivo models of neurological injury or neurodegenerative processes.

Immune System Modulation Research

Given Selank’s tuftsin origin, substantial research focuses on immunomodulatory applications:

• Lymphocyte Function Studies: Investigation of T-cell and B-cell activity modulation
• Cytokine Profile Research: Analysis of pro-inflammatory and anti-inflammatory cytokine expression
• Phagocytic Activity: Studies examining macrophage and neutrophil function
• Immune-Brain Axis: Research on bidirectional communication between immune and nervous systems
• Stress-Immune Interactions: Investigation of stress-induced immunosuppression mechanisms

Research in this area investigates Selank’s effects on immune cell populations, inflammatory markers, and the complex interactions between stress systems and immune function.

Neurotransmitter System Research

Selank provides a research tool for investigating multiple neurotransmitter systems:

• Monoamine Metabolism: Studies on serotonin, dopamine, and norepinephrine turnover rates
• Enzyme Expression Research: Investigation of MAO, COMT, and other metabolic enzyme modulation
• Receptor Expression Studies: Analysis of receptor density and sensitivity changes
• Synaptic Transmission: Research on neurotransmitter release, reuptake, and receptor binding
• Gene Expression Analysis: Investigation of transcriptional changes in neurotransmitter pathway genes

Laboratory investigations examine Selank’s effects through neurochemical analysis (HPLC, mass spectrometry), receptor binding assays, and molecular biology techniques.

Laboratory Handling and Storage Protocols

Lyophilized Powder Storage:

• Store at -20°C to -80°C in original sealed vial
• Protect from light exposure and moisture
• Desiccated storage environment required
• Stability data available for 12+ months at -20°C

Reconstitution Guidelines:

• Reconstitute with sterile water, bacteriostatic water (0.9% benzyl alcohol), or appropriate buffer
• Add solvent slowly down vial side to minimize foaming
• Gentle swirling motion recommended (avoid vigorous shaking)
• Allow complete dissolution before use (typically 1-2 minutes)
• Final pH should be 6.0-7.5 for optimal stability

Reconstituted Solution Storage:

• Short-term storage: 4°C for up to 7 days
• Long-term storage: -20°C in aliquots to avoid freeze-thaw cycles
• Single-use aliquots recommended to maintain peptide integrity
• Avoid repeated freeze-thaw cycles (maximum 2-3 cycles)

Stability Considerations:
Selank demonstrates enhanced stability compared to the parent tuftsin peptide due to C-terminal modifications. However, standard peptide handling protocols should be followed to maintain biological activity throughout experimental procedures.

Quality Assurance and Analytical Testing

Each Selank batch undergoes comprehensive analytical characterization:

Purity Analysis:

• High-Performance Liquid Chromatography (HPLC): ≥98% purity
• Analytical method: Reversed-phase HPLC with UV detection at 214nm
• Multiple peak integration to ensure accurate purity determination

Structural Verification:

• Electrospray Ionization Mass Spectrometry (ESI-MS): Confirms molecular weight 751.87 Da
• Amino acid analysis: Verifies sequence composition
• Peptide content determination: Quantifies actual peptide content by weight

Contaminant Testing:

• Bacterial endotoxin: <5 EU/mg (LAL method)
• Heavy metals: Below detection limits per USP standards
• Residual solvents: TFA and acetonitrile within acceptable limits
• Water content: Karl Fischer titration (<8%)

Documentation:

• Certificate of Analysis (COA) provided with each batch
• Third-party analytical verification available upon request
• Stability data documented for recommended storage conditions
• Batch-specific QC results traceable by lot number

Research Considerations

Experimental Design Factors:

Researchers should consider several factors when designing Selank experiments:

1. Administration Route: Intranasal administration demonstrates higher bioavailability in some experimental models compared to systemic routes. Route selection should align with research questions.

2. Concentration Selection: Determine appropriate concentrations based on research objectives, experimental model, and published literature. Dose-response relationships should be established for each experimental system.

3. Temporal Considerations: Selank’s effects may manifest at different time points for behavioral versus biochemical endpoints. Design measurement timelines accordingly.

4. Baseline Conditions: Consider stress state, circadian phase, and prior experience of experimental subjects, as these factors may influence response to Selank.

5. Control Groups: Include appropriate vehicle controls, stress-only controls, and comparative compounds (e.g., standard anxiolytics) where applicable.

Mechanism Investigation:

Selank’s mechanisms of action involve multiple systems. Investigated pathways include:

• GABAergic system modulation without direct receptor agonism
• Monoamine neurotransmitter metabolism and receptor expression
• Brain-derived neurotrophic factor (BDNF) upregulation
• Gene expression changes (enkephalins, neurotrophins)
• Immune system cytokine profile modulation

The peptide’s multiple potential mechanisms require careful experimental design to isolate specific effects and pathways.

Compliance and Safety Information

Regulatory Status:
Selank is provided as a research chemical for in-vitro laboratory studies and preclinical research only. This product has not been approved by the FDA for human therapeutic use, dietary supplementation, or medical applications.

Intended Use:

• In-vitro cell culture studies
• In-vivo preclinical research in approved animal models
• Laboratory investigation of biological mechanisms
• Academic and institutional research applications

NOT Intended For:

• Human consumption or administration
• Therapeutic treatment or diagnosis
• Dietary supplementation
• Veterinary therapeutic applications without appropriate oversight

Safety Protocols:
Researchers should follow standard laboratory safety practices when handling Selank:

• Use appropriate personal protective equipment (lab coat, gloves, safety glasses)
• Handle in well-ventilated areas or fume hood
• Follow institutional biosafety guidelines
• Dispose of waste according to local regulations for biological/chemical waste
• Consult material safety data sheet (MSDS) for additional safety information

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