drug affinity complex 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 2026-06-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| 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 |
Two related forms circulate in technical discussion under the same family name. The original version carries a drug affinity complex (DAC) that binds covalently to serum albumin after administration, and this linkage substantially extends circulation time. A second form, frequently written as modified GRF(1-29) or CJC-1295 without DAC, lacks that linker and clears much faster. The naming is a frequent source of confusion because the shorthand CJC-1295 can refer to either form depending on the source. Reports sometimes fail to specify which variant was studied.
The peptide backbone includes a D-alanine at position two, which resists cleavage by dipeptidyl peptidase IV, and several other substitutions that reduce degradation. Its molecular weight is roughly 3.4 kDa without the linker and about 3.6 kDa with it. The molecule is water soluble and is normally supplied as a lyophilized powder. Precise sequence and mass values depend on which variant is described, so technical documents usually state the exact form being referenced.
CJC-1295 is a synthetic peptide built as a long-acting analogue of growth hormone-releasing hormone. Its backbone matches the first twenty-nine residues of the natural human hormone, with four amino acid substitutions added to slow enzymatic breakdown. A reactive maleimide group, commonly termed the drug affinity complex, allows the peptide to attach to circulating albumin after administration. That albumin attachment keeps the molecule in the bloodstream for an extended period instead of being cleared within minutes.
The compound emerged from work at a Canadian biotechnology firm in the early 2000s. Early human studies examined its effect on growth hormone and insulin-like growth factor 1 in healthy volunteers and in people with HIV-associated fat redistribution. Reports described sustained increases in both markers after a single injection. Development did not advance to regulatory approval, and the clinical programme was later discontinued. The molecule is now encountered mainly as a research chemical rather than a marketed medicine.
== External links == vcclab.org. Overview of the many logP and other physical property calculators available commercially and on-line. XLOGP3, a simple LogP estimator used by PubChem (release 2021.05.07)
. The ratio of the stepwise stability constants can be calculated on this basis, but experimental ratios are not exactly the same because ΔH⊖ is not necessarily the same for each step. Exceptions to this rule are discussed below, in #chelate effect and #Geometrical factors.
=== Biodegradation === Some organisms are capable of metabolizing alkanes. The methane monooxygenases convert methane to methanol. For higher alkanes, cytochrome P450 convert alkanes to alcohols, which are then susceptible to degradation.
== Interactions == Unlike cimetidine, the first H2 antagonist, famotidine has a minimal effect on the cytochrome P450 enzyme system and does not appear to interact with as many drugs as other medications in its class. Some exceptions include antiretrovirals such as atazanavir, chemotherapeutics such as doxorubicin, and antifungal medications such as itraconazole.
He then moved to the Hebei province in North China, where he became a target of public scorn for being a remnant of the "old society", a belief that would only take further hold in China during The Cultural Revolution. He lived there in poverty for a few years before eventually becoming a monk. He finally moved back to Beijing after an unspecified amount of time and spent the remaining years of his life there, ostensibly as a caretaker of the Guanghua temple. Even with the faltering influence of the Qing Dynasty, Sun was nevertheless able to gain enough influence in the royal household to be privy to many of the court’s intimate secrets, such as the opium addiction and out-of-wedlock pregnancy of the Qing empress Wanrong, as well as reports that the emperor showed more interest in a eunuch than his wife. His preserved genitals, referred to as "treasure" by eunuchs as a slang term as well as in a literal fashion given the practice of eunuchs being buried with them as "complete men", were discarded by his siblings during the Cultural Revolution due to fear of persecution, given its connotation to the "old society". The fact that he could not be buried with his preserved genitals as a "complete man" remained a major source of distress for Sun for the remainder of his life.
Sources: en.wikipedia.org
Like the CNO-III, this branch is also only significant in massive stars. The reactions are started when one of the reactions in CNO-III results in fluorine-19 and a photon instead of nitrogen-15 and an alpha particle, and continues
=== Parasitic infections === HLA-G has been shown to modulate the body's response to parasitic diseases. Recent studies have emerged suggesting a link between HLA-G and Plasmodium falciparum, which is one of the most dangerous malaria species. In pregnant women, P. falciparum can infect the placenta, causing low birth weights and other complications. High levels of soluble HLA-G have been linked to higher instances of low birth weights. There is also a link between HLA-G expression and human African trypanosomiasis (HAT). People with higher levels of soluble HLA-G are more likely to be diagnosed with the disease. There may also be genetic differences driving the instance and severity of HAT, as a few single-nucleotide polymorphisms have been associated with higher levels of HAT. There is also an effect in toxoplasmosis infections in pregnant women, where HLA-G is upregulated to protect the fetus from inflammation. Treatment of cells with IL-10 leads to a downregulation of HLA-G, which could be an avenue for therapy in instances where too much HLA-G is produced. Individuals with visceral leishmaniasis infections also have higher levels of soluble HLA-G, which may be due to a strategy by Leishmania to evade the immune system.
=== From organic halides and cyanide salts === Two salt metathesis reactions are popular for laboratory scale reactions. In the Kolbe nitrile synthesis, alkyl halides undergo nucleophilic aliphatic substitution with alkali metal cyanides. Aryl nitriles are prepared in the Rosenmund-von Braun synthesis. In general, metal cyanides combine with alkyl halides to give a mixture of the nitrile and the isonitrile, although appropriate choice of counterion and temperature can minimize the latter. An alkyl sulfate obviates the problem entirely, particularly in nonaqueous conditions (the Pelouze synthesis). In the Kolbe nitrile synthesis (a nucleophilic substitution reaction), an alkanonitrile and an alkali halide are formed from a reactive halocarbons and an alkali cyanide (sodium cyanide or potassium cyanide). The reaction is particularly suitable for primary, allylic, and benzylic halides. Secondary alkyl halides provide lower yields, whereas tertiary halides undergo exclusively elimination reaction instead of substitution. In addition to halides, substrates bearing other good leaving groups may also be employed. In contrast to alkali cyanides, silver cyanide is unsuitable for nitrile synthesis, as it preferentially forms isonitriles. An example of the Kolbe nitrile synthesis is the reaction of methyl iodide with sodium cyanide to yield acetonitrile and sodium iodide:
=== Volatile compounds === Volatile compounds of green coffee beans include short-chain fatty acids, aldehydes, and nitrogen-containing aromatic molecules, such as derivatives of pyrazines (green-herbaceous-earthy odor). When green coffee beans are roasted, other molecules with the typical pleasant aroma of coffee are generated, which are not present in fresh green coffee. During roasting, the major part of the unpleasant-tasting volatile compounds are neutralized.
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 synthetic analogue modeled on the first 29 residues of human GHRH. The substitutions and any linker are laboratory modifications rather than features of the endogenous peptide.