GRF(1-29) is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-02-17. 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.
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.
Purity is most often assessed by reversed-phase high-performance liquid chromatography, reported as a percentage of total peak area. Identity is confirmed by mass spectrometry, which yields a molecular ion consistent with the expected sequence. Amino acid analysis and peptide mapping provide additional characterization. Reported purity values are method-dependent, so figures from different laboratories are not always directly comparable without details of column, gradient, and detection wavelength.
| 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 the name used for a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound was described by a Canadian drug discovery company in the mid-2000s as a long-acting research tool. Two closely related molecules share the name in practice: one carries a drug affinity complex, or DAC, group, and one does not. The distinction matters because the two behave differently in circulation.
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.
Characterization of this peptide relies on a small set of routine techniques. Reversed-phase high-performance liquid chromatography separates the target from truncated or oxidized by-products and yields a purity estimate when paired with ultraviolet detection near 214 nanometers. Mass spectrometry, either electrospray coupled to liquid chromatography or matrix-assisted laser desorption, confirms that the observed mass matches the value calculated for the expected sequence. Amino acid analysis, and enzymatic digestion followed by fragment mapping, are used when the sequence itself rather than the mass requires verification.
Stability depends heavily on physical state. A lyophilized powder kept dry, desiccated, and shielded from light typically holds its integrity for months to years at minus twenty degrees Celsius, and longer at minus eighty. Once dissolved, the peptide becomes far more vulnerable, since peptide bond hydrolysis, oxidation of susceptible residues, and aggregation all proceed faster in solution. Buffers near neutral pH are generally gentler than strongly acidic or alkaline conditions. Repeated freeze-thaw cycles and exposure to air-liquid interfaces during vigorous mixing cause losses that are easy to overlook.
Verification matters because research peptides vary widely in quality. A certificate of analysis is only as reliable as the method behind it, and a single chromatographic trace reveals little about counter-ions, residual solvents, or water content. Independent laboratories commonly pair mass confirmation with chromatographic purity and, where relevant, quantify water along with acetate or trifluoroacetate content. Reported purity figures are not standardized across suppliers, so a stated value such as ninety-eight percent is not directly comparable unless the analytical method, column, and detection wavelength accompany it.
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.
Alamethicin is a channel-forming peptide antibiotic, produced by the fungus Trichoderma viride. It belongs to peptaibol peptides which contain the non-proteinogenic amino acid residue Aib (2-aminoisobutyric acid). This residue strongly induces formation of alpha-helical structure. The peptide sequence is
== History == In traditional oil painting as practiced by the Renaissance painter, skin glue was used to seal the canvas. This is necessary because the linseed oil that forms the base of most oil paint contains linolenic acid that will destroy the canvas fibers over time. Renaissance artists also knew that pure size (hide glue) became brittle once dry, and would mix it with oil and chalk to make a "half-ground" for canvases. Pure hide glue was usually applied only to rigid supports like panels. Though this does help to seal the canvas or panel, artists still applied a layer of "oil ground", which was often lead-based paint, in order to provide a binding layer for the final oil paint to adhere to.
=== Names === Atomoxetine was originally known as tomoxetine. It was renamed to avoid medication errors, as the name may be confused with tamoxifen. In India, atomoxetine is sold under brand names including Axetra, Axepta, Attera, Tomoxetin, and Attentin. In Australia, Canada, Italy, Portugal, Romania, Spain, Switzerland, and the US, atomoxetine is sold under the brand name Strattera. In France, hospitals dispense atomoxetine under the brand name Strattera (it is not marketed in France). In the Czech Republic, it is sold under brand names including Mylan. In Poland, it is sold under the brand name Auroxetyn. In Indonesia, it is sold under the brand name Xenocy. In Iran, atomoxetine is sold under brand names including Stramox. In Brazil, it is sold under the brand name Atentah. In Turkey, it is sold under the brand names Attex, Setinox, and Atominex. In 2017, a generic version was approved in the United States.
Brazil occupies nearly half of the land area of South America (47.7%), including a large area along its eastern coast and much of the continent's interior. It borders Uruguay to the south; Argentina and Paraguay to the southwest; Bolivia and Peru to the west; Colombia to the northwest; and Venezuela, Guyana, Suriname, and France (French overseas region of French Guiana) to the north. It shares a border with every South American country except Ecuador and Chile. The Brazilian territory also encompasses a number of oceanic archipelagos, such as Fernando de Noronha, Rocas Atoll, Saint Peter and Saint Paul Archipelago, and the islands of Trindade and Martim Vaz. Its size, relief, climate, and natural resources make Brazil geographically diverse. Including its Atlantic islands, Brazil lies between latitudes 6°N and 34°S, and longitudes 28° and 74°W. Brazil is the fifth largest country in the world, and third largest in the Americas, with a total area of 8,515,767.049 km2 (3,287,956 sq mi), including 55,455 km2 (21,411 sq mi) of water. Brazil is the only country in the world that has the equator and the Tropic of Capricorn running through it. It spans four time zones; from UTC−5 comprising the state of Acre and the westernmost portion of Amazonas, to UTC−4 in the western states, to UTC−3 in the eastern states (the national time) and UTC−2 in the Atlantic islands.
Sources: en.wikipedia.org
=== Biosynthesis === Biosynthesis takes place in bacteria, fungi and plants, but not animals. The biosynthetic precursors to riboflavin are ribulose 5-phosphate and guanosine triphosphate. The former is converted to L-3,4-dihydroxy-2-butanone-4-phosphate. Guanosine is degraded to 4-hydroxy-2,4,5-triaminopyrimidine, which is transformed into 5-amino-6-(D-ribitylamino)uracil. These two compounds are then the substrates for the penultimate step in the pathway, catalysed by the enzyme lumazine synthase in reaction EC 2.5.1.78.
To model schizophrenia, animals were injected with phencyclidine (PCP) and, therefore, exhibited symptoms of the disorder, such as social withdrawal and motor responses. Upon injection with ZJ43, these behaviors were decreased, suggesting that an increase in NAAG in the synapse — and its subsequent activation of mGluR3 receptors — has potential as a co-therapy for schizophrenia. In these cases, NAAG peptidase inhibition reduces the adverse effects in these disorders. Future research focuses on the role of NAAG in pain perception, brain injury, and schizophrenia while developing NAAG peptidase inhibitors with even greater ability to cross the blood–brain barrier.[16][17]
Bush was engaged to Cathryn Lee Wolfman in 1967, but the engagement did not last. Bush and Wolfman remained on good terms after the end of the relationship. While Bush was at a backyard barbecue in 1977, friends introduced him to Laura Welch, a schoolteacher and librarian. After a three-month courtship, she accepted his marriage proposal and they wed on November 5 of that year. The couple settled in Midland, Texas. Bush left his family's Episcopal Church to join his wife's United Methodist Church. On November 25, 1981, Laura Bush gave birth to fraternal twin daughters, Barbara and Jenna. Bush describes being challenged by Billy Graham to consider faith in Jesus "Christ as the risen Lord", how he began reading the Bible daily, "surrendering" to "the Almighty", that "faith is a walk" and that he was "moved by God's love".
Sources: en.wikipedia.org
The process of RNAi was referred to as "co-suppression" and "quelling" when observed prior to the knowledge of an RNA-related mechanism. The discovery of RNAi was preceded first by observations of transcriptional inhibition by antisense RNA expressed in transgenic plants, and more directly by reports of unexpected outcomes in experiments performed by plant scientists in the United States and the Netherlands in the early 1990s. In an attempt to alter flower colors in petunias, researchers introduced additional copies of a gene encoding chalcone synthase, a key enzyme for flower pigmentation into petunia plants of normally pink or violet flower color. The overexpressed gene was expected to result in darker flowers, but instead caused some flowers to have less visible purple pigment, sometimes in variegated patterns, indicating that the activity of chalcone synthase had been substantially decreased or became suppressed in a context-specific manner. Another early observation of RNAi came from a study of the fungus Neurospora crassa, although it was not immediately recognized as related. Further investigation of the phenomenon in plants indicated that the downregulation was due to post-transcriptional inhibition of gene expression via an increased rate of mRNA degradation. This phenomenon was called co-suppression of gene expression, but the molecular mechanism remained unknown. Not long after, plant virologists working on improving plant resistance to viral diseases observed a similar unexpected phenomenon.
. The complexation of a metal ion implies therefore the replacement of the coordinated water molecules with the respective ligands. The speed of this substitution plays a crucial role in the complexation kinetics and the following extraction processes. The replacement can be slow for an inert complex or rapid for a labile complex. The ligand could replace all the coordinated water molecules to form an inner sphere complex or just some of them for an outer-sphere complex. The complexation reaction is theoretically based on the Pearson's theory of hard and soft acids and bases, according to which hard acids form strong complexes with hard bases and likewise soft acids form strong complexes with soft bases. In aqueous solutions, hard-hard interactions are electrostatic, while soft-soft interactions usually show a covalent character. The formation of strong complexes always implies either a large gain of entropy or a large decrease of enthalpy thereby obtaining a large negative value of the complexation free energy. According to Pearson's theory, lanthanide and actinide ions are considered hard acids, thus they bind especially with ligands bearing hard donors such as oxygen atoms by electrostatic interactions. The charge of actinide and lanthanide ions in solution is substantially +3 and the difference in size of these cations is very small. Thus, an efficient separation of minor actinides from lanthanides is very challenging.
The following month an attempted coup d'état was staged by a sector of the army that sought to paralyze the democratic process and that only the decisive intervention of King Juan Carlos I managed to stop. After 23-F, the new UCD government presided by Leopoldo Calvo Sotelo managed to rule largely thanks to the support given by the PSOE and its leader Felipe González because the "self-destruction" of the UCD continued until October 1982, when new elections were held and were won overwhelmingly by the PSOE. Thus a party that had been one of the defeated parties in the civil war of 1936–1939 took power. After 1982, the democratic system was consolidated and Spain experienced a long period of political stability in which there was alternation in government between the left and the right in a peaceful manner following the dictates of the elections (the PSOE governed between 1982 and 1996 and between 2004 and 2011; the People's Party, which emerged from the "refounding" in 1989 of the Alianza Popular, between 1996 and 2004 and between 2011 and 2014). It was decisive for the achievement of political stability that the positions of the two major parties on the most important issues were not antagonistic and that there were no major "social fractures", the latter thanks to the development of the Welfare state and "social protection" policies. Also during those years, Spain actively participated in the transformation of the European Community, which it joined in 1986, in the European Union and in the establishment of the common currency, the euro.
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.
Cool, dark, and dry conditions are standard, with storage at minus twenty degrees Celsius or below. Desiccant and sealed vials limit moisture uptake. Repeated warming and cooling of the container is generally avoided.