DSIP

DSIP Research Peptide: Comprehensive Laboratory Guide

DSIP research peptide, commonly expanded as delta sleep-inducing peptide or delta-sleep-inducing peptide, is a synthetic nonapeptide with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu. The abbreviation reflects the historical experiment in which peptide material isolated from rabbit cerebral venous blood was associated with changes in slow-wave electroencephalographic activity. That name should not be treated as proof of a single biological function. Later findings have varied across species, preparations, experimental schedules, analytical methods, and peptide analogues, while the endogenous precursor, a uniquely defined receptor, and the molecular identity of much reported “DSIP-like immunoreactivity” remain unresolved.

For that reason, DSIP is best presented as an investigational reagent for controlled biochemical, cellular, analytical, and nonclinical physiology research. It can support work on peptide identity, structure–activity relationships, neural signaling models, circadian measurements, neuroendocrine readouts, mitochondrial bioenergetics, and assay validation. This listing is strictly for qualified laboratory research. The currently configured 10 mg and 15 mg ten-vial variants are inventory formats only; they are not recommendations for an experiment or any other use. The material is not intended for humans or animals, diagnosis, prevention, treatment, food, cosmetics, or household use.

Molecular Identity and Product Overview

Product name	DSIP research peptide
Expanded name	Delta sleep-inducing peptide; delta-sleep-inducing peptide
Peptide length	9 amino-acid residues
Three-letter sequence	H-Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu-OH
One-letter sequence	WAGGDASGE
Molecular formula	C35H48N10O15
Average molecular mass	Approximately 848.8 g/mol
Exact monoisotopic mass	Approximately 848.3301 Da for the neutral defined peptide
PubChem CID	68816
Registry information	CAS 62568-57-4 and CAS 69431-45-4 are both encountered in records for DSIP-related material; verify the identity assigned to the exact lot and reference standard
Configured listing variants	10 mg × 10 vials or 15 mg × 10 vials; availability is variant-specific
Identity and purity	Lot-specific; consult the certificate of analysis and independently confirm the attributes required by the study
Use restriction	For nonclinical laboratory research only; not for human or animal use

The formula and mass describe the neutral, free-terminal peptide represented above. Gross vial mass may also include counterions, residual water, or other documented components. Catalog fill mass is therefore not a substitute for peptide-content testing. Researchers should distinguish intact molecular identity, chromatographic area purity, net peptide content, water, counterion, and model-relevant contaminants because each answers a different quality question.

Structural and Physicochemical Features

DSIP is a short, linear peptide with free amino and carboxyl termini. It contains one tryptophan residue, two alanines, three glycines, one aspartate, one serine, and one glutamate. The acidic side chains and C-terminus influence charge as pH changes, while the adjacent glycine residues contribute conformational flexibility. DSIP contains no cysteine and therefore has no native disulfide bond. It also lacks methionine, although oxidation of the tryptophan residue or other chemical changes may still be relevant during forced-degradation or long-term stability studies.

The single tryptophan provides ultraviolet absorbance near 280 nm, but UV response alone does not establish sequence, content, or purity. Extinction behavior can be affected by matrix and instrument conditions. Intact-mass spectrometry, tandem mass spectrometry, amino-acid analysis, and validated chromatographic methods provide complementary evidence. The Asp residue also deserves attention: historical structure–activity work distinguished the alpha-Asp peptide from a beta-Asp isomer. A simple intact-mass match may not separate such isomeric structures, so a fit-for-purpose chromatographic or fragmentation strategy may be necessary.

Solubility, adsorption, recovery, aggregation state, and solution stability cannot be inferred reliably from sequence alone. They may vary with pH, ionic strength, buffer composition, peptide level, contact surface, temperature, light, and handling history. Laboratories should establish compatibility in the actual assay matrix and labware. A generic statement about a universal solvent or universal solution lifetime would not be scientifically defensible.

Mechanistic and Research Themes

1. Historical Slow-Wave EEG Phenotype

The original rabbit studies linked isolated and synthetic DSIP with increased delta and spindle EEG activity under a specialized experimental protocol. Those experiments gave the peptide its name and established a testable phenotype, but they did not identify a receptor or demonstrate that DSIP is a universal physiological controller of sleep. Subsequent work reported species-specific, time-dependent, and sometimes absent or opposing patterns. Modern studies should treat the historical EEG observation as a model-specific starting point, use blinded scoring and preregistered spectral endpoints, and avoid converting an old nomenclature into a claim of established function.

The limited human literature is old, small, and mixed. A double-blind study in 16 participants with chronic insomnia reported weak changes in a subset of objective measures, no change in subjective sleep quality, and concluded that short-term DSIP treatment was unlikely to provide major therapeutic benefit. That clinical literature does not establish the safety, identity, or effectiveness of a catalog research reagent and is cited here only to define the evidence boundary.

2. Endogenous Identity and DSIP-Like Immunoreactivity

Immunoreactive material has been reported in neural and peripheral samples, yet antibody recognition does not necessarily prove that intact WAGGDASGE is present. Cross-reactive peptides, precursor fragments, modified species, or matrix effects may contribute to an immunoassay signal. The absence of a firmly established biosynthetic precursor and the uncertain relationship between synthetic DSIP and endogenous DSIP-like material remain central limitations. Research seeking endogenous evidence should combine immunoassay results with extraction controls, spike recovery, chromatographic separation, high-resolution mass spectrometry, and sequence-confirming fragmentation.

3. GABAergic and Glutamatergic Signaling Models

Experiments in rat cortical, hippocampal, and cerebellar preparations reported modulation of GABA-activated currents and NMDA-associated responses. These findings suggest that DSIP can be used as a probe in electrophysiology and synaptosome research. They do not establish a dedicated DSIP receptor, direct binding to a GABA or NMDA receptor, or equivalent behavior in other preparations. Membrane potential, receptor-subunit composition, cell region, species, peptide integrity, and background transmitter conditions can all change the result. Direct binding, channel modulation, transmitter release, and downstream network effects must be tested separately.

4. Indirect Opioid-System Interactions

An in vitro rat brainstem-slice study found release of immunoreactive Met-enkephalin while reporting no direct binding of DSIP to tested opioid-receptor subtypes. This distinction is important: a downstream change in an opioid-related readout is not evidence that DSIP itself is an opioid-receptor ligand. Follow-up work can compare intact peptide, sequence-scrambled controls, calcium dependence, release kinetics, receptor antagonism, and direct target-engagement assays. The result remains preparation-specific until replicated with orthogonal methods.

5. Circadian and Thermoregulatory Associations

Older studies explored relationships among DSIP-like immunoreactivity, time of day, sleep transitions, body temperature, locomotor patterns, and endocrine rhythms. Reported associations were not fully consistent and frequently relied on immunoreactivity rather than sequence-confirmed intact peptide. Circadian experiments should control clock time, light exposure, prior activity, feeding schedule, sampling stress, and repeated-measure structure. A correlation with a rhythmic variable cannot establish causal entrainment, and a plasma immunoassay signal cannot be assumed to represent neural concentration or receptor occupancy.

6. Neuroendocrine and Stress-Response Readouts

DSIP literature includes observations involving corticotropin-related signaling, corticosteroid measurements, growth-hormone-associated patterns, and stress models. Outcomes differ among protocols, and some controlled investigations did not reproduce earlier endocrine interpretations. These discrepancies make DSIP useful for studying experimental context rather than supporting a settled neuroendocrine mechanism. Strong designs separate baseline rhythm from stimulus response, specify sampling windows, include stress-matched controls, and measure upstream and downstream components instead of relying on a single hormone endpoint.

7. Mitochondrial Bioenergetics

Work with isolated rat brain mitochondria and homogenates reported changes in phosphorylating respiration, respiratory control, and ADP phosphorylation under defined conditions. Such findings provide a basis for testing whether DSIP influences mitochondrial efficiency directly or through components retained in the preparation. They do not demonstrate a universal antioxidant or protective effect. Oxygen-consumption assays should include substrate definition, coupling controls, membrane-integrity checks, normalization to mitochondrial content, vehicle and sequence controls, and an orthogonal measure of ATP-linked function.

8. Structure–Activity and Modified-Peptide Research

Historical comparisons of fragments, substituted analogues, the beta-Asp isomer, and phosphorylated DSIP-related species indicate that sequence and chemical form can materially alter assay behavior. Results from DSIP fragments or modified analogues should not be attributed automatically to the parent nonapeptide. Conversely, a nominal DSIP result may reflect degradation if identity is not checked after incubation. Structure–activity studies should document terminal state, stereochemistry, Asp linkage, phosphorylation status, purity, and stability in the experimental matrix.

Appropriate Nonclinical Research Applications

Neuropeptide Identity and Endogenous-Detection Studies

DSIP can serve as a synthetic reference for developing targeted LC-MS/MS methods intended to distinguish intact peptide from cross-reactive or co-eluting material. Researchers can evaluate extraction recovery, matrix suppression, fragmentation ions, retention behavior, and lower limits of reliable identification. Stable-isotope internal standards, blank matrices, carryover checks, and immunoaffinity controls can strengthen conclusions about endogenous samples.

Electrophysiology and Neurotransmission Models

Neuronal cultures, acute slices, synaptosomes, or receptor-defined systems may be used to explore GABAergic and glutamatergic readouts. Suitable endpoints include current amplitude, kinetics, calcium flux, transmitter release, receptor trafficking, and downstream phosphosignaling. Use vehicle, positive controls, sequence-scrambled peptide, pathway blockers, viability measures, and washout or recovery conditions. Claims of direct target engagement require direct evidence rather than a downstream functional response alone.

Circadian and EEG Method Development

Nonclinical protocols can use DSIP as one investigational condition in studies of spectral EEG analysis, state scoring, circadian phase, or sleep–wake transitions. Randomization, blinded scoring, acclimation, stable environmental timing, predefined frequency bands, and adequate biological replication are essential. Because the literature is heterogeneous, replication of a historical phenotype and an exploratory mechanism study should be framed as separate objectives.

Neuroendocrine Signaling Research

Cellular, ex vivo, or approved nonclinical models may examine associations with stress-responsive endocrine pathways. Multiplex measurements are more informative than an isolated endpoint when paired with temporal sampling and appropriate reference conditions. Investigators should distinguish secretion, synthesis, clearance, and assay interference. Contradictory results are valuable if the methods, timing, peptide identity, and biological context are documented transparently.

Mitochondrial Respiration and Stress Models

Isolated mitochondria, permeabilized cells, or tissue homogenates can be used to test oxygen consumption, respiratory coupling, membrane potential, redox state, and ATP-linked output. A result in an isolated preparation should be interpreted at that level and not generalized to an intact organism. Peptide stability, nonspecific protein binding, substrate availability, mitochondrial quality, and normalization method should be assessed before mechanistic conclusions are drawn.

Peptide Stability and Impurity Profiling

The short sequence supports method development for intact mass, fragmentation, reversed-phase separation, adsorption recovery, and forced degradation. Laboratories can monitor oxidation, Asp-related isomerization, truncation, hydrolysis, aggregation, or surface loss where relevant. A stability-indicating method must resolve the intact target from important related species and should use a qualified reference rather than retention time alone.

Analytical and Quality-Control Framework

1. Document provenance. Record supplier, lot number, labeled form, manufacturing or test date, shipping condition, storage history, vial condition, and all available certificates.
2. Confirm intact identity. Compare observed high-resolution mass with the expected DSIP structure and evaluate relevant charge states, adducts, and system suitability.
3. Support sequence assignment. Use tandem mass spectrometry, peptide mapping, or another orthogonal method when sequence, terminal state, or Asp linkage matters.
4. Assess related substances. Apply a qualified chromatographic method and define how peaks are integrated, identified, and reported.
5. Measure peptide content. Do not equate an area-purity percentage with the amount of intact peptide in the vial.
6. Evaluate recovery. Test adsorption, matrix effects, freeze–thaw exposure, and container compatibility under the actual analytical conditions.
7. Check model-relevant contaminants. Endotoxin, bioburden, particulates, synthesis residuals, or counterions may matter depending on the assay.
8. Retain evidence. Preserve chromatograms, spectra, integration parameters, sample histories, acceptance criteria, and reserve material.

HPLC area purity is method-dependent. It does not independently establish identity, peptide content, stereochemical form, biological activity, sterility, endotoxin status, or suitability for a specific model. Likewise, an intact-mass match does not exclude every isomer or low-level impurity. Fit-for-purpose qualification normally combines chemical identity, quantitative content, impurity assessment, recovery, and model-relevant controls.

Experimental Design and Interpretation

Begin with a defined hypothesis and a documented acceptance plan. At minimum, include untreated and vehicle controls, a qualified positive control where available, peptide-only and stimulus-only conditions, and a sequence or matrix control appropriate to the assay. Separate technical replicates from independent biological replicates. Randomize plate position or acquisition order, blind subjective analysis, and predefine exclusion criteria before viewing outcomes.

Peptide integrity should be confirmed at a scientifically relevant point, especially in long incubations or complex matrices. A negative biological result may reflect adsorption or degradation, while an unexpected positive result may reflect contamination, matrix effects, or an impurity. When studying signaling, combine an early proximal measurement with a later functional endpoint. Genetic perturbation, selective inhibitors, rescue experiments, and direct binding methods answer different mechanistic questions and should not be treated as interchangeable.

For circadian or time-series work, align sampling to a defined reference phase and use statistical models that account for repeated measurements and rhythmic structure. For multiple cytokines, metabolites, or spectral bands, prespecify primary outcomes and control multiplicity. Report effect sizes, confidence intervals, raw-data availability, peptide lot, and analytical qualification so that apparently conflicting findings can be compared.

Laboratory Handling and Storage

Only trained personnel should handle DSIP research material under an institutional risk assessment and laboratory SOP. Use appropriate personal protective equipment, prevent aerosol or surface contamination, and keep the reagent clearly labeled and segregated from food, medicines, clinical supplies, and personal items. Consult the lot-specific safety and quality documentation; this product page does not establish a universal hazard classification.

Follow the labeled storage condition and certificate for the exact lot. Protect material from avoidable moisture, heat, light, and repeated temperature cycling. For analytical solutions, use a validated laboratory procedure based on measured solubility, recovery, and stability in the selected matrix. Low-binding labware and single-work-session aliquots may be evaluated where surface loss or repeated handling affects recovery. Record preparation time, buffer, container, temperature history, and analytical confirmation.

No universal preparation protocol or solution lifetime is provided because peptide behavior is method- and matrix-dependent. Catalog vial size does not define an experimental condition. The receiving laboratory is responsible for method validation, biosafety review, compliant storage, traceability, and disposal.

Frequently Asked Questions

1. What is DSIP?

DSIP is a nine-residue peptide with the sequence WAGGDASGE. Its name comes from historical rabbit EEG research, but contemporary reviews emphasize that its endogenous precursor, dedicated receptor, and precise physiological role remain uncertain. This product is a synthetic reference material for controlled laboratory research, not a consumer product.

2. Does the name prove that DSIP induces sleep?

No. The name records the phenotype reported in early experiments; it is not proof of a universal or reproducible effect. Results have varied with model, species, timing, analytical method, and peptide form. Studies should measure predefined endpoints under blinded, controlled conditions and describe conclusions at the level supported by the data.

3. Is there a confirmed DSIP receptor?

No uniquely defined, high-affinity DSIP receptor has been conclusively established. GABAergic, glutamatergic, opioid-related, endocrine, and mitochondrial observations are pathway or phenotype findings, not automatic evidence of direct binding. Target-engagement claims require appropriate binding, structural, genetic, or biophysical evidence.

4. Why is DSIP-like immunoreactivity not the same as intact DSIP?

An antibody may recognize related sequences, modified peptides, precursor fragments, or interfering matrix components. Immunoreactivity should therefore be confirmed through separation, spike-recovery controls, and sequence-specific mass spectrometry when exact molecular identity matters. A numerical immunoassay result alone cannot prove intact WAGGDASGE.

5. Which analytical methods are useful?

Commonly useful approaches include high-resolution LC-MS, tandem mass spectrometry, reversed-phase HPLC or UHPLC, amino-acid analysis, and validated quantitative assays. Method choice depends on whether the question concerns identity, sequence, purity, content, stability, adsorption, or an endogenous matrix. Orthogonal methods provide stronger evidence than one chromatographic peak.

6. Are the 10 mg and 15 mg options experimental recommendations?

No. They are catalog fill-size variants supplied as ten-vial configurations. They do not specify a suitable assay condition, biological model, or protocol. Qualified investigators must establish conditions from their hypothesis, validated method, material qualification, controls, institutional approvals, and applicable regulations.

7. Is this material appropriate for human or animal use?

No. Hanpro supplies this DSIP material exclusively for nonclinical laboratory research. It is not intended for diagnosis, prevention, treatment, consumption, compounding, or use in humans or animals. Published biological observations do not establish the identity, safety, or performance of a catalog reagent outside a qualified research protocol.

Related Research Materials

• Semax — a synthetic peptide material for nonclinical neurobiology and signaling research.
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• Pinealon — a short peptide material for cellular-stress and neurobiology research.
• Epithalon — a tetrapeptide reference for aging-related, cellular, and chronobiology-oriented research.
• VIP — a defined neuropeptide material for receptor, circadian, and neuroimmune models.
• Oxytocin Acetate — a defined neuropeptide material for receptor and neuroendocrine studies.
• Humanin — a mitochondrial-derived peptide material for cellular-stress research.
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• Thymalin — a peptide-mixture research material for comparative bioregulator assays.
• Vilon — a short peptide research material for comparative cellular-signaling studies.

Quality Documentation

Request and review the certificate that corresponds to the exact lot received. Useful records may include intact-mass identity, chromatographic purity, stated peptide form, peptide content, counterion information, residual water, and model-relevant tests. Methods and specifications vary, so the receiving laboratory must determine whether the reported evidence is sufficient for its intended study.

Do not infer sterile status, a specific endotoxin limit, sequence confirmation, validated biological potency, or absence of a particular impurity unless the lot documentation explicitly reports a suitable test. Retain receiving records, raw analytical data, method versions, and reserve material when traceability matters. Independent confirmation helps protect reproducibility and data interpretation.

Selected Authoritative References

1. National Center for Biotechnology Information. PubChem Compound Summary for CID 68816, Delta Sleep-Inducing Peptide. View the PubChem record.
2. Schoenenberger GA, Monnier M. Characterization of a delta-electroencephalogram (-sleep)-inducing peptide. Proceedings of the National Academy of Sciences of the USA. 1977;74(3):1282–1286. PubMed PMID 265572.
3. Schoenenberger GA, Maier PF, Tobler HJ, Wilson K, Monnier M. The delta EEG (sleep)-inducing peptide. XI. Amino-acid analysis, sequence, synthesis and activity of the nonapeptide. Pflügers Archiv. 1978;376(2):119–129. PubMed PMID 568769.
4. Kovalzon VM, Strekalova TV. Delta sleep-inducing peptide (DSIP): a still unresolved riddle. Journal of Neurochemistry. 2006;97(2):303–309. PubMed PMID 16539679.
5. Grigor’ev VV, et al. Effects of delta sleep-inducing peptide on pre- and postsynaptic glutamate and postsynaptic GABA receptors in neurons of the cortex, hippocampus, and cerebellum in rats. Bulletin of Experimental Biology and Medicine. 2006;142(2):186–188. PubMed PMID 17369935.
6. Nakamura A, Nakashima M, Sakai K, Niwa M, Nozaki M, Shiomi H. Delta-sleep-inducing peptide stimulates the release of immunoreactive Met-enkephalin from rat lower brainstem slices in vitro. Brain Research. 1989. PubMed PMID 2706459.
7. Khvatova EM, Samartzev VN, Zagoskin PP, Prudchenko IA, Mikhaleva II. Delta sleep inducing peptide: effect on respiration activity in rat brain mitochondria and stress protective potency under experimental hypoxia. Peptides. 2003;24(2):307–311. PubMed PMID 12668217.
8. Seifritz E, et al. Human plasma DSIP decreases at the initiation of sleep at different circadian times. Peptides. 1995;16(8):1475–1481. PubMed PMID 8745061.
9. Graf MV, Saegesser B, Schoenenberger GA. Degradation and aggregation of DSIP and two analogs in plasma and serum. Peptides. 1987;8(4):599–603. PubMed PMID 3628078.
10. Bes F, Hofman W, Schuur J, Van Boxtel C. Effects of DSIP on sleep of chronic insomniac patients: a double-blind study. Neuropsychobiology. 1992;26(4):193–197. PubMed PMID 1299794.

Research-use disclaimer: This DSIP research peptide is supplied exclusively to qualified professionals for nonclinical laboratory investigation. It is not a medicine, diagnostic product, food, dietary supplement, cosmetic, veterinary product, or household item, and it is not for human or animal use. Nothing on this page constitutes medical advice or establishes safety or effectiveness. Investigators are responsible for institutional review, risk assessment, method validation, legal compliance, traceability, and safe disposal.