The short version of drug affinity complex fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-09-07. Anything still debated is marked as such rather than presented as settled.
CJC-1295 is a synthetic peptide designed as a long-acting analogue of growth hormone-releasing hormone (GHRH). Its structure derives from the first 29 amino acids of native GHRH, a fragment often called GRF(1-29). Four substitutions were introduced to slow enzymatic breakdown and extend activity relative to the natural sequence. The compound was developed by ConjuChem as part of a broader effort to improve the pharmacokinetic profile of peptide hormones. It is studied in laboratory and clinical research settings rather than appearing as a naturally occurring substance.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular weight (no linker) | ~3.37 kDa | Calculated from peptide sequence |
| Molecular weight (with linker) | ~3.65 kDa | Includes albumin-binding moiety |
| Appearance | White to off-white powder | Typically lyophilized |
| Solubility | Soluble in water | Also dissolves in aqueous buffers |
| Common synonyms | Modified GRF(1-29), DAC:GRF | Usage varies by source |
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.
The second form adds a maleimide-bearing linker to the lysine at the carboxyl end. This group reacts with cysteine-34 on circulating serum albumin, forming a covalent bond that keeps the peptide in the bloodstream for far longer. ConjuChem developed the molecule as a way to extend the action of a peptide without frequent administration. The albumin attachment is the defining structural feature of the drug affinity complex version. Whether continuous exposure produces effects distinct from shorter pulses remains an unresolved research question.
The peptide binds GHRH receptors on somatotroph cells within the anterior pituitary, triggering a signalling cascade that increases growth hormone secretion. Its improved resistance to dipeptidyl peptidase IV degradation distinguishes it from the parent hormone. In the DAC-bearing version, a maleimide group reacts with a cysteine residue on serum albumin, forming a covalent bond that keeps the peptide in circulation far longer. That albumin attachment is the central design feature separating the two research variants.
Pharmacokinetic behaviour differs sharply between the two forms. The DAC-bearing peptide shows an extended circulation time measured in days, whereas the version without the complex is cleared within roughly half an hour. This gap shapes how researchers design dosing schedules in animal models. Whether the prolonged presence of the DAC form produces effects meaningfully different from the short-acting variant remains an open question, since comparative human data are scarce.
GlcA = β-D-glucuronic acid, IdoA = α-L-iduronic acid, IdoA(2S) = 2-O-sulfo-α-L-iduronic acid, GlcNAc = 2-deoxy-2-acetamido-α-D-glucopyranosyl, GlcNS = 2-deoxy-2-sulfamido-α-D-glucopyranosyl, GlcNS(6S) = 2-deoxy-2-sulfamido-α-D-glucopyranosyl-6-O-sulfate One unit of heparin (the "Howell unit") is an amount approximately equivalent to 0.002 mg of pure heparin, which is the quantity required to keep 1 ml of cat's blood fluid for 24 hours at 0 °C.
The relatively recent emergence of Salvia divinorum in modern Western culture, in comparison to its long continuing traditions of Indigenous use, contrasts widely differing attitudes on the subject. Opinions range from veneration of the plant as a spiritual sacrament or "a gift from the gods" to a "threat to society," to be banned as quickly as possible in order to "spare countless families the horror of losing a loved one to the relentless tentacles of drug abuse".
Topical nonsteroidal anti-inflammatory drugs provide pain relief in common conditions such as muscle sprains and overuse injuries. Since the side effects are also lesser, topical preparations could be preferred over oral medications in these conditions.
For substances in solution, the isoelectric point (pI) is defined as the pH at which the sum, weighted by charge value, of concentrations of positively charged species is equal to the weighted sum of concentrations of negatively charged species. In the case that there is one species of each type, the isoelectric point can be obtained directly from the pK values. Take the example of glycine, defined as AH. There are two dissociation equilibria to consider.
Sources: en.wikipedia.org
On Czapek Yeast Extract Agar medium at 25 °C, white colonies grow in a plane, attaining a velvety to deeply floccose texture, with colony sizes that are 33–35 mm in diameter. On this medium, olive conidia are produced. The reverse of the plate can be pale or slightly tinted brown. On Malt Extract Agar medium at 25 °C, growth is rare, yet rapid when occurring, forming a velvety surface. At first, colonies are yellow-green, but ultimately turn olive due to conidial production. Colony diameter can range in size from 35 mm to 70 mm. The reverse of the plate is similar to that observed for Czapek Yeast Extract Agar medium. On 25% Glycerol Nitrate Agar at 25 °C, colony growth is planar, yet develops into a thick gel, with colony size diameter ranging from 6–12 mm. The back of the plate is described as pale or olive. At 5 °C, 25% Glycerol Nitrate Agar supports germination and a colonial growth of up to 3 mm in diameter. This species fails to grow at 37 °C. On Creatine Sucrose Agar at 25 °C, colony size diameter ranges from 4 to 10 mm. Growth is restricted, and medium pH remains around 7. No change on the back of the plate is noted. Growth on media containing orange fruit pieces for seven days at room temperature results in fruit decay, accompanied by a characteristic odour. After 14 days at room temperature, the reverse is colourless to light brown.
Most white Rhodesians felt that they were due independence following four decades of self-government, and that the British government was betraying them by withholding it. A stalemate developed between the British and Rhodesian prime ministers, Harold Wilson and Ian Smith respectively, between 1964 and 1965. The dispute largely surrounded the British condition that the terms for independence had to be acceptable "to the people of the country as a whole"; Smith contended that this was met, while the UK and African Nationalist Rhodesian leaders held that it was not. After Wilson proposed in late October 1965 that the UK might safeguard future black representation in the Rhodesian parliament by withdrawing some of the colonial government's devolved powers, then presented terms for an investigatory Royal Commission that the Rhodesians found unacceptable, Smith and his Cabinet declared independence. Calling this treasonous, the British colonial governor, Sir Humphrey Gibbs, formally dismissed Smith and his government, but they ignored him and appointed an "Officer Administering the Government" to take his place. While no country recognised the UDI, the Rhodesian High Court deemed the post-UDI government legal and de jure in 1968. The Smith administration initially professed continued loyalty to Queen Elizabeth II, but abandoned this in 1970 when it declared a republic in an unsuccessful attempt to win foreign recognition.
== Research == Other related drugs under development by Helus Pharma (formerly Cybin) include the deuterated phenethylamine HLP005 (CYB005) and the deuterated tryptamines deupsilocin (HLP003; CYB003) and deudimethyltryptamine (HLP004; CYB004).
=== Lodotra === "Lodotra" is the brand name of an oral formulation, which releases prednisone four hours after ingestion. It is indicated for rheumatoid arthritis with morning stiffness. Taken at 10 p.m., it releases the drug at around 2 a.m. The plasmic peak level is reached at 4 a.m., which is considered to be the optimal time for relieving morning stiffness. The drug was approved in the European Union, in January 2009.
The agreement specified that this agreement was only with Amat-Mamu, and no other person could lay claim to Belessunu's estate by providing for her. Two years after the agreement was made, two of Belessunu's cousins and fellow nadītus—Amat-Šamaš and Nīši-īnīšu—laid claim to the fields. The mayor of Sippar, Zimri-Erah, ruled that the inheritance was rightfully Belessunu's. The cousins were penalized for making a false claim over property, and they were forced to give Amat-Mamu a tablet that relinquished their claims. Professor Rivkah Harris speculated that Belessunu passed over her cousins in favor of Amat-Mamu because Amat-Mamu was a member of a wealthy family and therefore better able to support Belessunu during her life.
Sources: en.wikipedia.org
February 20: Decrees enacting the Conventions on the night work of women and of children in industry, drawn up in Washington by the International Labor Conference and signed in Paris on January 24, 1921, by France and Belgium, along with their annexed protocol. August 10: Nationality law. December 6: Decree on the regulations of the École nationale supérieure de céramique in Sèvres, reserved for boys. 1928
The Latam Pulse survey, carried out by Atlasintel and released on 11 February, showed that President Lula had 45.9% approval and 51.4% disapproval, the worst mark in the historical series. Rejection is higher among men, young people aged 16 to 44, evangelicals, and residents of the Central-West, North, South, and Southeast regions. In the Northeast, the rates are balanced. The overall evaluation of the government also worsened, with 46.5% considering the administration bad or terrible. Concern about the economy doubled, being cited by 29% of Brazilians, behind only crime (58%) and corruption (49%). Inflation is the biggest economic problem, mentioned by 75% of respondents. On tax reform, 41.5% considered it progress in need of improvement, 23% saw it as progress, and 35% classified it as a setback. The Datafolha survey, released by Folha de S.Paulo on 14 February, points to a fall in President Lula's approval, recording the lowest rate of his three terms. According to the survey, 24% of respondents rated the government as excellent or good, while 41% considered it bad or terrible. Another 32% classified the administration as regular, and 2% did not know how to respond. Compared with the previous survey, carried out in December 2024, approval fell from 35% to 24%, while disapproval increased from 34% to 41%. The fall was observed in different segments. Among voters with income of up to two minimum wages, approval fell from 44% to 29%. Among those earning more than ten minimum wages, it went from 32% to 18%.
== History == Zalcitabine was first synthesized in the 1960s by Jerome Horwitz and subsequently developed as an anti-HIV agent by Samuel Broder, Hiroaki Mitsuya, and Robert Yarchoan at the National Cancer Institute (NCI). Like didanosine, it was then licensed because the NCI may not market or sell drugs. The National Institutes of Health (NIH) thus licensed it to Hoffmann-La Roche.
Apamin is an 18 amino acid globular peptide neurotoxin found in apitoxin (bee venom). Dry bee venom consists of 2–3% of apamin. Apamin selectively blocks SK channels, a type of Ca2+-activated K+ channel expressed in the central nervous system. Toxicity is caused by only a few amino acids, in particular cysteine1, lysine4, arginine13, arginine14 and histidine18. These amino acids are involved in the binding of apamin to the Ca2+-activated K+ channel. Due to its specificity for SK channels, apamin is used as a drug in biomedical research to study the electrical properties of SK channels and their role in the afterhyperpolarizations occurring immediately following an action potential.
Sources: en.wikipedia.org
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.
Early development used the albumin-binding form, and a shorter variant was later discussed under the same label. Because the two differ in half-life and handling, ambiguity arises whenever a source omits the variant designation.
The compound derives from that fragment but is not identical to it. The parent fragment lacks the stabilizing substitutions, so its degradation rate and duration of action differ noticeably.
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.