This is a working overview of lyophilized powder, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-07-24 and is reviewed periodically as new material appears.
CJC-1295 is a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. Its sequence corresponds to the first twenty-nine residues of human GHRH, with four substitutions that slow enzymatic breakdown. Early descriptions placed the compound in research on growth hormone deficiency and related conditions, and later literature groups it with the long-acting GHRH analogs. The name appears in both laboratory and popular fitness writing, where it sometimes labels chemically different peptides.
Two related peptides circulate under the CJC-1295 label, and they differ mainly in how long they persist in circulation. The version carrying a drug affinity complex includes a maleimidopropionic acid linker that forms a covalent bond with serum albumin. The other version, usually written as modified GRF(1-29) or tetrasubstituted GRF(1-29), lacks that linker and is cleared quickly. Mixing the two produces inconsistent readings of published half-life values, because the linker rather than the receptor-facing sequence drives most of the difference.
The core sequence keeps the receptor-binding region of GHRH while replacing four positions that are vulnerable to dipeptidyl peptidase-4 and other proteases. Substitutions at positions 2, 8, 15, and 27 raise metabolic stability relative to the natural hormone. The N-terminal residues remain essential for activity, so changes there generally lower potency. Molecular weight sits near 3368 daltons for the tetrasubstituted analog without the linker, while the albumin-binding form is heavier because of the added maleimide group.
Once in circulation, the peptide binds the growth hormone-releasing hormone receptor displayed on pituitary somatotroph cells. Receptor activation couples to Gs proteins, elevates intracellular cyclic AMP, and drives protein kinase A signaling inside the cell. That cascade increases discharge of growth hormone into the bloodstream. The analog therefore operates through a receptor pathway that already exists for the body's own releasing hormone, rather than through an engineered artificial target.
Clearance profiles diverge sharply between the two versions. The albumin-binding molecule stays in plasma for several days, whereas the unmodified analog is largely gone within about half an hour in reported work. Cleavage by dipeptidyl peptidase IV is a major contributor to the short life of the unmodified sequence. These gaps mean the two versions cannot be substituted for each other in study design or in reading results side by side.
| Property | Value | Notes |
|---|---|---|
| Class | Synthetic peptide | GHRH receptor agonist |
| Sequence length | 29 amino acids | Derived from human GHRH |
| Molecular weight | About 3368 Da without linker | Albumin-binding form is heavier |
| Appearance | White to off-white lyophilized powder | Common form for research reference material |
| Typical storage | -20 °C or below, desiccated | Protect powder from light and moisture |
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.
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.
CJC-1295 is a synthetic analogue of growth hormone-releasing hormone, built on the 29-amino-acid GHRH(1-29) fragment. Four substitutions distinguish it from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes reduce enzymatic cleavage and extend the peptide's persistence in circulation. The compound is discussed in two forms, one carrying a drug affinity complex and one without it.
The drug affinity complex is a maleimidopropionic acid group attached to a lysine side chain. It reacts with the free thiol of cysteine-34 on circulating albumin, forming a covalent bond. This conjugation keeps the peptide in the bloodstream and shields it from rapid renal filtration and proteolysis. Reported circulation half-lives for the albumin-bound form fall in the range of roughly six to nine days in early human studies.
Binding to GHRH receptors on pituitary somatotroph cells triggers cyclic AMP signaling and stimulates growth hormone synthesis and release. Because the peptide acts upstream of the pituitary, effects are mediated through endogenous growth hormone rather than direct receptor activation in peripheral tissues. Increases in insulin-like growth factor 1 are generally described as a downstream consequence. Most published human exposure data come from small early-stage studies, and the clinical significance of the pharmacokinetic profile remains incompletely characterized.
== Pathobiochemie == Ein Protein-S-Mangel kann dementsprechend zu Thrombosen führen. Ein heterozygoter Gendefekt führt dabei zu einem erhöhten Risiko, eine venöse Thrombose zu erleiden. Ein homozygoter Gendefekt ist nicht mit dem Leben vereinbar, betroffene Patienten erleiden bereits während der Fetalperiode ernste Thrombosen oder leiden unter Störungen der Entwicklung des Gefäßsystems.
== Literatur == A. Lundwall, W. Dackowski, E. Cohen, M. Shaffer, A. Mahr, B. Dahlbäck, J. Stenflo, R. Wydro: Isolation and sequence of the cDNA for human protein S, a regulator of blood coagulation. In: Proc. Natl. Acad. Sci. U.S.A. 83 (18), Sept. 1986, S. 6716–6720. doi:10.1073/pnas.83.18.6716. PMC 386580 (freier Volltext). PMID 2944113. G. L. Long, A. Marshall, J. C. Gardner, S. L. Naylor: Genes for human vitamin K-dependent plasma proteins C and S are located on chromosomes 2 and 3, respectively. In: Somat. Cell Mol. Genet. 14 (1), Jan 1988, S. 93–98. doi:10.1007/BF01535052. PMID 2829367. E. Castoldi, T. M. Hackeng: Regulation of coagulation by protein S. In: Curr. Opin. Hematol. 15 (5), Sept. 2008, S. 529–536. doi:10.1097/MOH.0b013e328309ec97. PMID 18695379. Eckhard Podack, William Kolb, Hans Müller-Eberhard: The SC5b-7 complex: formation, isolation, properties, and subunit composition. In: J. Immunol. 199, 1977, S. 2024–2029. PMID 410885. N. J. Beauchamp, A. C. Dykes, N. Parikh, R. Campbell Tait, M. E. Daly: The prevalence of, and molecular defects underlying, inherited protein S deficiency in the general population. In: Br. J. Haematol. 125 (5), Jun 2004, S. 647–654. doi:10.1111/j.1365-2141.2004.04961.x. PMID 15147381. P. García de Frutos, P. Fuentes-Prior, B. Hurtado, N. Sala: Molecular basis of protein S deficiency. In: Thromb. Haemost. 98 (3), Sept. 2007, S. 543–556. doi:10.1160/th07-03-0199. PMID 17849042. M. J. Heeb, Y. Kojima, J. Rosing, G. Tans, J. H. Griffin: C-terminal residues 621-635 of protein S are essential for binding to factor Va. In: J. Biol. Chem.
(UNITED STATES) 274 (51), Dez 1999, S. 36187–36192. doi:10.1074/jbc.274.51.36187. PMID 10593904. M. J. Heeb, R. M. Mesters, G. Tans, J. Rosing, J. H. Griffin: Binding of protein S to factor Va associated with inhibition of prothrombinase that is independent of activated protein C. In: J. Biol. Chem. (UNITED STATES) 268 (4), Feb 1993, S. 2872–2877. PMID 8428962.
Sources: de.wikipedia.org
Protein Z ist ein Vitamin-K-abhängiges Glykoprotein im Blutplasma, welches in der Leber gebildet wird und an der Blutgerinnung beteiligt ist. Protein Z hat eine molare Masse von 62 kDa und besteht aus 360 Aminosäuren. Es wurde 1977 zunächst bei Rindern, 1984 beim Menschen nachgewiesen. Protein Z ist an der Gerinnung beteiligt, indem es eine Anlagerung von Thrombin an endotheliale Phospholipidoberflächen unterstützt und mit Hilfe eines spezifischen Protease-Inhibitors die prokoagulatorische Aktivität des Faktors Xa hemmt. Protein Z hat dabei aber selbst keine katalytische Funktion. Ein verminderter Spiegel von Protein Z wird mit Thrombosen sowie mit Fehlgeburten in Verbindung gebracht.
Sources: de.wikipedia.org
Natural GHRH is degraded quickly by dipeptidyl peptidase-4 and related enzymes, giving it a half-life measured in minutes. CJC-1295 carries substitutions that slow that breakdown, so it stays intact longer. Both act at the same pituitary receptor and produce the same class of signal.
The label was first attached to the albumin-binding form during early development work. A shorter analog without the linker later became known by the same name in informal use. Published papers normally state which version was studied, so the methods section resolves the ambiguity.
It is a synthetic peptide rather than a steroid, and it does not occur naturally in the body. Its sequence is derived from a hypothalamic hormone called growth hormone-releasing hormone. It works as a receptor agonist rather than as a replacement for that hormone.
It acts on the growth hormone-releasing hormone receptor found on pituitary somatotroph cells. Activation of that receptor triggers growth hormone release through a cyclic AMP dependent pathway.