The short version of GHRH analog fits in a sentence. The long version — which is the one that helps — is below.
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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.
CJC-1295 belongs to a family of synthetic peptides modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound is built from the first twenty-nine amino acids of the natural human sequence, a fragment that retains full receptor binding capacity. Native growth hormone-releasing hormone is degraded quickly in circulation, so the fragment alone has limited practical value. Early work therefore focused on chemical modifications that preserve receptor binding while slowing enzymatic breakdown. The result is a molecule described in the literature as a long-acting analog of the natural hormone.
Two forms circulate under the CJC-1295 name, and they differ by a single appended group. The version without a drug affinity complex carries four substitutions along the peptide chain, including a D-alanine near the amino terminus and replacements at three other positions. These changes block the enzyme dipeptidyl peptidase IV and remove a methionine residue that is prone to oxidation. The modified fragment is frequently labeled MOD GRF 1-29. Naming conventions are inconsistent across informal sources, which is a common source of confusion.
| 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 |
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.
Four amino acid substitutions separate the modified backbone from the parent GRF(1-29) sequence. These changes reduce recognition by dipeptidyl peptidase IV and related proteases, extending the interval before degradation. Development work in this area sought longer-acting GHRH analogs for endocrine investigation. Published descriptions treat the substitution set as a defining property of the core sequence, while the albumin-binding linker is described separately as an optional addition to that same backbone.
The albumin-binding version stays in circulation for days, because covalent attachment to serum albumin shields the peptide from rapid filtration and degradation. Reported half-lives for this form fall in the range of several days. The version without the linker is cleared in minutes, with estimates often near thirty minutes in animal work. These figures come from small studies and vary with assay method, species, and route, so they are best read as approximate rather than fixed constants.
Studies in this area generally track growth hormone pulses, insulin-like growth factor 1 concentrations, and occasionally body composition endpoints. Most published human data come from early, small trials, and questions about long-term effects remain open. Whether repeated exposure alters pituitary responsiveness over time is not settled. Analytical work relies on immunoassays for the hormones and on mass spectrometry for the peptide itself, because the two measurements answer different questions.
Binding of the peptide to the growth hormone-releasing hormone receptor on pituitary somatotrophs triggers a G protein coupled cascade that raises cyclic AMP and opens calcium channels. The result is greater secretion of growth hormone into the bloodstream. Because the peptide acts at the same receptor as the natural hypothalamic hormone, its effect is amplified pulse size rather than an entirely separate release pathway. Receptor binding alone does not determine the response, since somatostatin tone and other inputs modulate the final output.
Glutathione S-transferase theta-2 is an enzyme that in humans is encoded by the GSTT2 gene. Glutathione S-transferase (GSTs) theta 2 (GSTT2) is a member of a superfamily of proteins that catalyze the conjugation of reduced glutathione to a variety of electrophilic and hydrophobic compounds. Human GSTs can be divided into five main classes: Alpha, Mu, Pi, Theta, and Zeta. The theta class members GSTT1 and GSTT2 share 55% amino acid sequence identity and both are thought to have an important role in human carcinogenesis. The theta genes have a similar structure, being composed of five exons with identical exon/intron boundaries.
== Coiled coils == Coiled-coil α helices are highly stable forms in which two or more helices wrap around each other in a "supercoil" structure. Coiled coils contain a highly characteristic sequence motif known as a heptad repeat, in which the motif repeats itself every seven residues along the sequence (amino acid residues, not DNA base-pairs). The first and especially the fourth residues (known as the a and d positions) are almost always hydrophobic; the fourth residue is typically leucine – this gives rise to the name of the structural motif called a leucine zipper, which is a type of coiled-coil. These hydrophobic residues pack together in the interior of the helix bundle. In general, the fifth and seventh residues (the e and g positions) have opposing charges and form a salt bridge stabilized by electrostatic interactions. Fibrous proteins such as keratin or the "stalks" of myosin or kinesin often adopt coiled-coil structures, as do several dimerizing proteins. A pair of coiled-coils – a four-helix bundle – is a very common structural motif in proteins. For example, it occurs in human growth hormone and several varieties of cytochrome. The Rop protein, which promotes plasmid replication in bacteria, is an interesting case in which a single polypeptide forms a coiled-coil and two monomers assemble to form a four-helix bundle.
A March 2007 survey of public opinion in six Arab nations conducted by Zogby International and the University of Maryland found that Bush was the most disliked world leader. During a June 2007 visit to the predominantly Muslim Albania, Bush was greeted enthusiastically. Albania has a population of 2.8 million, has troops in both Iraq and Afghanistan, and the country's government is highly supportive of American foreign policy. A huge image of the President was hung in the middle of the capital city of Tirana flanked by Albanian and American flags while a local street was named after him. A shirt-sleeved statue of Bush was unveiled in Fushë-Krujë, a few kilometers northwest of Tirana. The Bush administration's support for the unilateral declaration of independence of Albanian-majority Kosovo, while endearing him to the Albanians, troubled U.S. relations with Serbia, leading to the February 2008 torching of the U.S. embassy in Belgrade.
=== First isolation and classification === Proteins were recognized as a distinct class of biological molecules in the eighteenth century by Antoine Fourcroy and others. Members of this class (called the "albuminoids", Eiweisskörper, or matières albuminoides) were recognized by their ability to coagulate or flocculate under various treatments such as heat or acid; well-known examples at the start of the nineteenth century included albumen from egg whites, blood serum albumin, fibrin, and wheat gluten. The similarity between the cooking of egg whites and the curdling of milk was recognized even in ancient times; for example, the name albumen for the egg-white protein was coined by Pliny the Elder from the Latin albus ovi (egg white). With the advice of Jöns Jakob Berzelius, the Dutch chemist Gerhardus Johannes Mulder carried out elemental analyses of common animal and plant proteins. To everyone's surprise, all proteins had nearly the same empirical formula, roughly C400H620N100O120 with individual sulfur and phosphorus atoms. Mulder published his findings in two papers (1837,1838) and hypothesized that there was one basic substance (Grundstoff) of proteins, and that it was synthesized by plants and absorbed from them by animals in digestion. Berzelius was an early proponent of this theory and proposed the name "protein" for this substance in a letter dated 10 July 1838
Sources: en.wikipedia.org
== External links == Imidazoline+Receptors at the U.S. National Library of Medicine Medical Subject Headings (MeSH) imidazoline receptor 2 at the U.S. National Library of Medicine Medical Subject Headings (MeSH) imidazoline I1 receptors at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
== Further reading == Moskin, Julia (August 19, 2014). "Brisket Is Worth the Wait". The New York Times. Retrieved March 17, 2015. Green, Aliza (2005). Field Guide to Meat. Philadelphia: Quirk Books. ISBN 1-931686-79-3.
This series of lists omits periods from acronyms and initialisms. It uses periods for certain abbreviations that traditionally often have them (mostly older Latin/Neo-Latin abbreviations). For example, both bid and b.i.d. may be found in the list. It generally uses the singular form of an abbreviation (not the plural) as the headword. This list uses significant capitalization for headwords (the abbreviations) and their expansions.
Sources: en.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.
No. It is a laboratory-synthesized analog built on a fragment of the natural hormone. The natural peptide is shorter-lived and lacks the stabilizing substitutions found in the synthetic version.