A practical reference on DAC: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-05-16. Anything still debated is marked as such rather than presented as settled.
Two related forms appear under the CJC-1295 name. The simpler analogue, commonly written as modified GRF(1-29), carries the four substitutions but no additional conjugation. The second form attaches a maleimidopropionic acid linker to a lysine residue, a modification frequently called the drug affinity complex. That linker reacts with the free thiol on serum albumin to form a covalent bond. Because albumin has a long residence time in blood, the conjugated peptide stays in circulation far longer than the unconjugated analogue.
Receptor level activity follows the canonical GHRH pathway. The peptide binds the GHRH receptor, a class B G protein coupled receptor on somatotroph cells of the anterior pituitary. Binding raises intracellular cyclic AMP, which promotes calcium entry and the release of growth hormone into the bloodstream. Because the molecule acts at the same receptor as the endogenous hormone, its effect is superimposed on the natural pulsatile rhythm rather than replacing it. Whether sustained receptor occupation leads to desensitization is not fully settled.
CJC-1295 belongs to a class of synthetic peptides modeled on growth hormone releasing hormone, a forty-four amino acid signal produced by the hypothalamus. The compound is built from the first twenty-nine residues of the natural sequence, with four substitutions introduced at positions 2, 8, 15 and 27. These changes were designed to slow enzymatic breakdown while preserving receptor activation. The result is a peptide that is shorter than native GHRH and considerably more resistant to ordinary clearance pathways in circulation.
CJC-1295 is a synthetic peptide belonging to the growth hormone-releasing hormone analog family. It comprises twenty-nine amino acid residues derived from the N-terminal region of natural GHRH. The molecule incorporates several non-natural substitutions that increase resistance to enzymatic degradation. These modifications extend its activity compared with the native hormone fragment. Researchers use it to study pituitary growth hormone secretion in laboratory and clinical settings. This compound is distinct from native GHRH in its stability profile.
Two principal forms appear in the literature and in research supply. One carries a drug affinity complex, a maleimide-based group that forms a covalent bond with circulating albumin. This linkage slows clearance and produces a long-lasting elevation of peptide levels. The other form lacks that group and is often labeled MOD GRF(1-29). It has a much shorter circulation time. Both variants retain the same core receptor-binding sequence. Reported half-lives differ substantially between the two.
| Property | Value | Notes |
|---|---|---|
| Peptide class | Synthetic GHRH analogue | Built on a 29 residue sequence |
| Primary target | GHRH receptor (GHRHR) | Class B G protein coupled receptor |
| Unconjugated half life | Minutes | Limited by protease degradation |
| Key modification | Four residue substitutions | Positions 2, 8, 15 and 27 |
| Common synonym | Modified GRF(1-29) | Usually denotes the form without DAC |
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.
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.
CJC-1295 acts at the growth hormone-releasing hormone receptor, a G-protein-coupled receptor found on somatotroph cells in the anterior pituitary. Binding triggers a rise in cyclic AMP and calcium entry, which promotes release of stored growth hormone. Because the peptide mimics the body's own releasing hormone, it amplifies existing secretory pulses rather than driving continuous output. The size of the response therefore depends partly on the subject's own hormonal rhythm and feedback state.
The attached maleimide group explains the unusual duration of the DAC version. After injection it reacts with the thiol of cysteine-34 on serum albumin, forming a stable covalent bond. The resulting conjugate is too large for rapid kidney filtration and is shielded from many peptidases. Reported half-lives for this form reach several days, whereas the version without the group is cleared in roughly half an hour. That gap is the main pharmacological difference between the two.
Lyophilised powder is the usual supplied form. The material is hygroscopic, so vials are typically equilibrated to room temperature before opening in order to prevent condensation on the contents. Long-term storage is generally described at minus twenty degrees Celsius or colder, protected from light and moisture. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of soluble material. A reconstituted solution is considerably less stable than the dry powder and is normally kept refrigerated for short periods only.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography combined with mass spectrometry. The chromatographic separation resolves the target peptide from truncation products and from species carrying oxidised residues, while mass measurement confirms the expected molecular mass. Because the two common variants differ by roughly 280 daltons, a mass determination distinguishes them unambiguously. Purity is often quoted as a percentage of total peak area, although that figure depends on the detection wavelength and the integration method applied.
An anticancer drug is coupled to an antibody that targets a specific tumor antigen (or protein) that, ideally, is only found in or on tumor cells. The biochemical reaction that occurs upon attaching triggers a signal in the tumor cell, which then absorbs, or internalizes, the antibody together with the linked cytotoxin. After the ADC is internalized, the cytotoxin kills the cancer. Their targeting ability was believed to limit side effects for cancer patients and to give a wider therapeutic window than other chemotherapeutic agents, although this promise hasn't yet been realized in the clinic. ADC technologies have been featured in many publications, including scientific journals.
Righthanded β-helices, typified by the pectate lyase enzyme shown at left or P22 phage tailspike protein, have a less regular cross-section, longer and indented on one of the sides; of the three linker loops, one is consistently just two residues long and the others are variable, often elaborated to form a binding or active site. A two-sided β-helix (right-handed) is found in some bacterial metalloproteases; its two loops are each six residues long and bind stabilizing calcium ions to maintain the integrity of the structure, using the backbone and the Asp side chain oxygens of a GGXGXD sequence motif. This fold is called a β-roll in the SCOP classification.
As anti-angiogenic cancer therapies have achieved widespread use, there has been increased interest in non-invasive monitoring of angiogenesis. One of the most extensively examined targets of angiogenesis is integrin αVβ3. Radiolabeled peptides containing RGD show high affinity and selectivity for integrin αVβ3 and are being investigated as tools to monitor treatment response of tumors via PET imaging. These include 18F-Galacto-RGD, 18F-Fluciclatide-RGD, 18F-RGD-K5, 68Ga-NOTA-RGD, 68Ga-NOTA-PRGD2, 18F-Alfatide, 18F-Alfatide II, and 18F-FPPRGD2. In a meta-analysis of studies using PET/CT in patients with cancer, it was shown that this diagnostic method may be very useful for detecting malignancies and predicting short-term outcomes, although larger-scale studies are needed.
Sources: en.wikipedia.org
TP0586532 is an experimental antibiotic drug, which acts as a potent and selective inhibitor of the bacterial enzyme UDP-3-O-acyl-N-acetylglucosamine deacetylase (LpxC). This enzyme is important for the production of Lipid A, a key component of the cell membrane of Gram-negative bacteria. Previous inhibitors of LpxC have failed to progress into clinical trials in humans, mostly because of off-target cardiovascular toxicity, so TP0586532 was based on a different structural class which is hoped to reduce this risk. In animal studies it shows activity against carbapenem-resistant Klebsiella pneumoniae but has not yet progressed into human trials. LPC-233
Tissue engineering aims to generate functional constructs which could replace or improve damaged or infected tissues or whole organs. Many of these constructs lead to infected tissue around the implant area. Coating these materials in amylopectin allows reduction in this infectious reaction. Since amylopectin is mainly used as a coating around these constructs in as it prevents following immune reactions. Since amylopectin is derived directly from a natural polysaccharide, it integrates well with tissues and cells. However, mechanical properties of amylopectin are not optimal due to its high level of crosslinking. This can be avoided by the formation of amylopectin fibers or by forming a nanocomposite with another more rigid polymer.
The period from 1958 to 1968 saw tremendous growth in aviation. Improvements in aviation safety and accident investigation procedures were rapidly advancing. In 1963, the Civil Aeronautics Board, under the leadership of then Deputy Director Bobbie R. Allen, established the National Aircraft Accident Investigation School in Oklahoma City. The ICAO's third accident investigation division meeting, held in Montreal, Canada, in January 1965, laid the foundation for accident investigations throughout the world. The proposals were presented by the Director of the Civil Aeronautics Board Bureau of Safety, Bobbie R. Allen, who headed the U.S. delegation. The U.S. formally adopted the proposals at the White House on December 1, 1965. The top 10 countries with the highest number of fatal civil airliner accidents from 1945 to 2021 are the United States, Russia, Canada, Brazil, Colombia, United Kingdom, France, Indonesia, Mexico, and India. The United Kingdom is noted to have the highest number of air crashes in Europe, with a total of 110 air crashes within the time period, and Indonesia is the highest in Asia at 104, followed by India at 95.
Sources: en.wikipedia.org
Mammals begin carbohydrate synthesis with monosaccharides, which come from either gluconeogenesis or the breakdown of complex carbohydrates. Gluconeogenesis begins with pyruvate, which comes from alanine and α-ketoglutarate amino acids. This process only begins when glycogen storages are near depletion due to the higher ATP cost of metabolising proteins into amino acids. Conversely, plants undergo the Calvin cycle to photosynthesize glucose-3-phosphate from CO2 and H2O in the presence of light; the phosphate is quickly hydrolyzed into glucose.
Aviation Safety Network Established in 1996. The ASN Safety Database contains descriptions of over 15800 airliner, military and corporate jet aircraft accidents/incidents since 1921. Bureau of Aircraft Accidents Archives Established in 2000. The B3A contains descriptions of over 22,000 airliner, military and corporate jet aircraft accidents since 1918. National Transportation Safety Board Aviation Accident Synopses – by month Aviation Statistics Statistical and geospatial analysis of general aviation accidents. Aviation Accidents App Access the NTSB Aviation Accidents Database and Final Reports from all over the world on your mobile device Aviation Accidents Map Explore an interactive map showcasing airplane crash sites Air Crash Map | Interactive Aviation Accident Database
The clinical significance of bilirubin glucuronide is involved in many conditions. Drugs that inhibit the activities of the components involved in bilirubin metabolism can give rise to accumulation of bilirubin in the blood. In comparison, conjugation of some drugs is also usually impaired if the liver cannot normally metabolize indirect bilirubin. When excretion of bilirubin glucuronide by the kidney is detected in the urine through urine examination, meaning that a conspicuous amount of conjugated bilirubin is present and circulating in the blood. In Dubin–Johnson syndrome, impaired biliary excretion of bilirubin glucuronide is due to a mutation in the canalicular multiple drug-resistance protein 2 (MRP2). A darkly pigmented liver is due to polymerized epinephrine metabolites, not bilirubin.
Sources: en.wikipedia.org
The names are often used interchangeably in casual writing, but they are not strictly identical. Modified GRF(1-29) refers to the unconjugated analogue carrying only the four substitutions. The version sold as CJC-1295 with DAC includes the albumin binding linker and clears much more slowly.
DAC stands for drug affinity complex, a term describing the maleimidopropionic acid linker. This group forms a covalent bond with the cysteine residue on serum albumin after administration. The resulting adduct is what extends the circulating half life from minutes to days.
No. It is entirely synthetic and does not correspond to any known endogenous peptide. The design starts from human growth hormone releasing hormone and introduces deliberate substitutions. Any biological effect comes from mimicking the natural hormone at its receptor.
It is a synthetic peptide modeled on growth hormone-releasing hormone. The molecule is used in research on pituitary growth hormone secretion. It differs from the natural hormone through several stabilizing substitutions.