GRF(1-29) comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-11-14. Where a claim depends on a specific study, the study is described rather than over-claimed.
Laboratory handling centers on minimizing exposure to water, heat and oxygen before use. Working solutions are typically prepared in sterile water or a mild buffer, and any residual particulate matter is removed by filtration. When the powder dissolves slowly, a small proportion of acetonitrile or dilute acetic acid is sometimes added as a co-solvent. Containers are kept sealed and desiccated between uses. Records of lot number, reconstitution date and storage conditions support later comparison of results across experiments.
Identity and purity are established with reversed phase high performance liquid chromatography coupled to mass spectrometry. The chromatographic step separates the target peptide from truncated sequences and deletion products, while the mass measurement confirms the expected molecular weight to within a fraction of a dalton. Because the two common variants differ by the presence of the linker, mass alone can distinguish them in the unconjugated state. Amino acid analysis and peptide mapping are used when sequence level confirmation is required.
Lyophilized material is generally stable for extended periods when held at minus twenty degrees Celsius or below and protected from moisture and light. In solution the peptide is more labile; bond hydrolysis, aggregation and oxidation of susceptible residues all proceed faster at ambient temperature. Repeated freeze and thaw cycles should be avoided because they promote clumping and loss of soluble material. The conjugated variant adds a further consideration, since the maleimide group can hydrolyze in aqueous buffer and lose its ability to react with albumin.
The peptide backbone corresponds to GRF(1-29), the first 29 residues of native growth hormone-releasing hormone, which retains most of the receptor-activating activity of the full-length molecule. Four substitutions distinguish the analog from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes slow cleavage by dipeptidyl peptidase IV, the enzyme that degrades native hormone in plasma within minutes. The outcome is improved enzymatic stability combined with a still brief residence time when no additional modification is present.
Naming in this area is inconsistent, and readers should treat product labels with care. In much of the literature and in vendor catalogs, the unqualified term refers to the albumin-binding version, while the version lacking the DAC group appears as modified GRF(1-29), mod GRF(1-29), or the same name with a without-DAC qualifier. Because one abbreviation has been applied to both materials, the only reliable way to identify a sample is to check the stated sequence and the presence of the linker.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off white powder | Typical lyophilized form |
| Water solubility | Soluble | May need a small organic co-solvent |
| Purity assessment | Chromatographic peak area | Most certificates report a percentage figure |
| Storage temperature | Minus 20 C or lower | Dry, dark, sealed container |
| Identity check | Electrospray mass spectrometry | Compared against theoretical mass |
CJC-1295 is a synthetic peptide analog of growth hormone-releasing hormone, constructed on the 29-amino-acid fragment designated GRF(1-29). The name began as an internal development code during the 1990s and later spread through research supply catalogs and discussion forums. The molecule does not occur in nature; its sequence is engineered rather than isolated from tissue. Two related compounds are sold under this single label, and they differ by one appended chemical group that strongly influences how long the peptide remains in circulation.
The dividing feature between the two forms is a maleimide-based drug affinity complex, abbreviated DAC. In the DAC-bearing version, a linker attaches the peptide to serum albumin after administration, and that association slows removal from plasma. The version lacking DAC appears in catalogs as MOD GRF(1-29) or tetrasubstituted GRF(1-29). Because informal writing treats both as one item, comparisons drawn from such sources routinely blend measurements taken from two molecules with substantially different behavior.
Peptide degradation proceeds mainly through hydrolysis, oxidation of methionine, and deamidation of asparagine or glutamine residues. The maleimide group on the albumin-binding variant can also react with thiols or hydrolyze in aqueous media. Because these pathways accelerate with temperature and pH extremes, handling conditions strongly influence measured stability. Stability data in the public literature are limited and often generated under differing conditions, so general statements about shelf life should be read as approximate.
Research material is normally supplied as a freeze-dried powder in sealed vials. In that state the peptide is comparatively robust, but prolonged exposure to warmth, moisture, or light accelerates degradation. Storage at minus twenty degrees Celsius or lower, with desiccant and protection from light, is the commonly described practice. Vials should be allowed to reach room temperature before opening to limit condensation on the powder. Moisture uptake during handling is a recognized source of variability in later measurements.
Reconstitution is typically performed with sterile water or bacteriostatic water, added slowly against the vial wall. The resulting solution should be clear and colorless; cloudiness or visible particles suggest a problem with the material or the diluent. Once in solution, the peptide is less stable than the dry powder. Refrigerated storage at two to eight degrees Celsius is common for short-term holding, while freezing aliquots is described for longer periods.
=== SELDI surface === The binding of proteins to the SELDI surface acts as a solid-phase chromatographic separation step, and as a result, the proteins attached to the surface are easier to analyze. The surface is composed primarily of materials with a variety of physico-chemical characteristics, metal ions, or anion or cation exchangers. Common surfaces include CM10 (weak cation exchange), H50 (hydrophobic surface, similar to C6-C12 reverse phase chromatography), IMAC30 (metal-binding surface), and Q10 (strong anion exchange). SELDI surfaces can also be modified to study DNA-protein binding, antibody-antigen assays, and receptor-ligand interactions.
When the analytical concentration of methylamine is twice that of ethylenediamine and the concentration of copper is the same in both reactions, the concentration [Cu(en)]2+ is much higher than the concentration [Cu(MeNH2)2]2+ because β11 ≫ β12. The difference between the two stability constants is mainly due to the difference in the standard entropy change, ΔS⊖. In the reaction with the chelating ligand there are two particles on the left and one on the right, whereas in equation with the monodentate ligand there are three particles on the left and one on the right. This means that less entropy of disorder is lost when the chelate complex is formed than when the complex with monodentate ligands is formed. This is one of the factors contributing to the entropy difference. Other factors include solvation changes and ring formation. Some experimental data to illustrate the effect are shown in the following table.
=== Mass-18 notation === Under some circumstances, the abundances of 13CH3D and 12CH2D2 isotopologues are only measured as a sum, which leads to the notation for isotopologues of mass-18 (i.e. 13CH3D and 12CH2D2):
== History == Doxylamine is a first-generation antihistamine and was discovered by Nathan Sperber and colleagues and was first reported in 1948 or 1949. It has been the antihistamine component of NyQuil since 1966. Bendectin, a combination of doxylamine, pyridoxine (vitamin B6), and dicyclomine (an anticholinergic antispasmodic agent), was marketed for treatment of morning sickness in 1956. This product was reformulated in 1976 to remove dicyclomine. The reformulated product was voluntarily discontinued by the manufacturer in the United States in 1983 due to concerns about an alleged association with congenital limb defects. However, these concerns have not been supported by studies. In 2013, doxylamine/pyridoxine was reintroduced in the United States under the brand name Diclegis. The combination was not removed from the market in Canada, where it had been marketed since 1979.
Sources: en.wikipedia.org
A coup d'état ( ; French: [ku deta] ; lit. 'stroke of state'), or simply a coup, is typically an illegal and overt attempt by a military organization or other government elites to unseat an incumbent person or leadership. A self-coup is said to take place when a leader, having come to power through legal means, tries to stay in power through illegal means. By one estimate, there were 457 coup attempts from 1950 to 2010, half of which were successful. Most coup attempts occurred in the mid-1960s, but there were also large numbers of coup attempts in the mid-1970s and the early 1990s. Coups occurring in the post-Cold War period have been more likely to result in democratic systems than Cold War coups, though coups still mostly perpetuate authoritarianism. Many factors may lead to the occurrence of a coup, as well as determine the success or failure of a coup. Once a coup is underway, coup success is driven by coup-makers' ability to get others to believe that the coup attempt will be successful. The number of successful coups has decreased over time. Failed coups in authoritarian systems are likely to strengthen the power of the authoritarian ruler. The cumulative number of coups is a strong predictor of future coups, a phenomenon referred to as the "coup trap". In what is referred to as "coup-proofing", regimes create structures that make it hard for any small group to seize power. These coup-proofing strategies may include the strategic placing of family, ethnic, and religious groups in the military and the fragmenting of military and security agencies.
Ricin is very toxic if inhaled, injected, or ingested. It can also be toxic if dust contacts the eyes or if it is absorbed through damaged skin. It acts as a toxin by inhibiting protein synthesis. Ricin is resistant, but not impervious, to digestion by peptidases. By ingestion, the pathology of ricin is largely restricted to the gastrointestinal tract, where it may cause mucosal injuries. With appropriate treatment, most patients will make a good recovery.
== Effects on animals == Ecological exposure in water has severe toxic effects on wildlife. When adult and larval zebrafish were exposed to various concentrations of DBNPA, significant morphological changes and mortality rates were observed. Even relatively low concentrations of DBNPA can have detrimental effects on zebrafish embryonic development, and high concentrations resulted in rapid mortality in adult zebrafish and larvae. DBNPA is highly toxic to mammals and birds concerning acute oral inhalation, but has low toxicity to birds concerning consummation of food. The pesticide is moderately toxic to freshwater fish, estuarine fish and shrimp; moderately to highly toxic to freshwater crustaceans; and highly to very highly toxic to estuarine shellfish and larvae. Many effects to aquatic organisms occur within 24 hours of exposure. Residual antibiotics in meat were previously found to disrupt its fermentation, increase the risk of infection, and make pathogens less susceptible medically to treatment with antibiotics. Apparently, antibiotics found at low concentrations at the end of the ethanol process can cause high levels of antimicrobial resistance. These problems can be avoided by the application of DBNPA instead of an antibiotic to control bacteria in the ethanol process. This represents a significant advance in the field because DBNPA breaks down prior to the end of the process and thus cannot enter DDGS used for animal foods.
Sources: en.wikipedia.org
== Further reading == Brady LS, Lisanby SH, Gordon JA (2023). "New directions in psychiatric drug development: promising therapeutics in the pipeline". Expert Opin Drug Discov. 18 (8): 835–850. doi:10.1080/17460441.2023.2224555. PMID 37352473. PhRMA. "2023 Medicines in Development – Mental Illness" (PDF). PhRMA. Retrieved 5 August 2024.
consistent, clinically established pharmacodynamic relationships between plasma drug concentrations and pharmacological efficacy and/or toxicity; significant between-patient pharmacokinetic variability, making a standard dosage achieve different concentration levels among patients (while the drug disposition remains relatively stable in a given patient); narrow therapeutic window of the drug, which forbids giving high doses in all patients to ensure overall efficacy; drug dosage optimization not achievable based on clinical observation alone; duration of the treatment and criticality for patient's condition justifying dosage adjustment efforts; potential patient compliance problems that might be remedied through concentration monitoring. TDM determinations are also used to detect and diagnose poisoning with drugs, should the suspicion arise. Examples of drugs widely analysed for therapeutic drug monitoring:
Avoiding smoking Cutting down on fats to help reduce the amount of plaque buildup Eating a healthy diet, including plenty of fruits and vegetables Limiting sodium in the diet, thereby reducing blood pressure Exercising regularly Moderating intake of alcohol, stimulants, sympathomimetics, etc. Maintaining a healthy weight In addition, it is important to control any underlying medical conditions that may increase the risk of stroke or TIA, including:
Sources: en.wikipedia.org
The mass difference from the linker is large enough for routine detection by mass spectrometry. The unconjugated form gives a single sharp signal at its expected weight. Material that has already reacted with albumin shows a much higher mass and a broadened chromatographic peak.
Yes. Degradation proceeds faster once the powder is dissolved, especially at room temperature or after multiple freeze and thaw cycles. Working solutions are often aliquoted to avoid repeated handling. Lyophilized powder held cold and dry retains its properties far longer.
Truncated sequences, oxidized residues and aggregated forms can all elute near the main peak. Reversed phase chromatography resolves many of these species, so the number of peaks is a useful indicator of synthesis quality. A single peak does not by itself prove correct sequence, which is why mass confirmation is paired with it.
No. It is a laboratory-made analog of growth hormone-releasing hormone. The natural hormone is a 44-residue peptide, while the analog is built on a shorter 29-residue fragment.