This is a working overview of drug affinity complex, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-07-15. Anything still debated is marked as such rather than presented as settled.
The distinguishing feature of the DAC form is a maleimide-containing group that reacts with the free thiol of cysteine-34 on human serum albumin. This reaction forms a covalent bond without enzymatic assistance, and it takes place after the peptide enters the bloodstream. Because albumin is abundant and long-lived, the attached peptide is carried through circulation far longer than an unmodified fragment would survive. The chemistry is a deliberate pharmacokinetic strategy rather than a change to receptor activity.
Enzymatic protection is a separate mechanism from plasma protein binding. The four substitutions in the backbone reduce recognition by dipeptidyl peptidase IV, which normally cleaves the natural hormone within minutes. Without the reactive group, this resistance still yields only a short window of activity, generally reported in the range of tens of minutes. With it, reported half-lives in early human work extended to several days. The size of that gap is the main practical distinction between the two materials.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Duration with linker | Several days | Reported in early human work |
| Duration without linker | Tens of minutes | Short plasma residence |
| Albumin attachment site | Cysteine-34 | Covalent maleimide reaction |
| Primary receptor | Pituitary GHRH receptor | Stimulates growth hormone release |
| Downstream marker | Insulin-like growth factor 1 | Indirect measure of activity |
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.
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.
Two forms circulate in research settings and are frequently confused. One carries the drug affinity complex and is often written as CJC-1295 with DAC; the other lacks that group and is usually called modified GRF(1-29). The two share the same core sequence but differ sharply in how long they persist in blood. Products labelled only as CJC-1295 normally refer to the version carrying the complex. Documentation that omits the distinction leaves the intended molecule ambiguous.
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.
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.
Characterization of this peptide relies on a small set of routine techniques. Reversed-phase high-performance liquid chromatography separates the target from truncated or oxidized by-products and yields a purity estimate when paired with ultraviolet detection near 214 nanometers. Mass spectrometry, either electrospray coupled to liquid chromatography or matrix-assisted laser desorption, confirms that the observed mass matches the value calculated for the expected sequence. Amino acid analysis, and enzymatic digestion followed by fragment mapping, are used when the sequence itself rather than the mass requires verification.
Stability depends heavily on physical state. A lyophilized powder kept dry, desiccated, and shielded from light typically holds its integrity for months to years at minus twenty degrees Celsius, and longer at minus eighty. Once dissolved, the peptide becomes far more vulnerable, since peptide bond hydrolysis, oxidation of susceptible residues, and aggregation all proceed faster in solution. Buffers near neutral pH are generally gentler than strongly acidic or alkaline conditions. Repeated freeze-thaw cycles and exposure to air-liquid interfaces during vigorous mixing cause losses that are easy to overlook.
Xi was re-elected as general secretary and CMC chairman by the 19th Central Committee after the 19th Party National Congress, held between 18 and 24 October 2017; the 19th Politburo was noted for containing no potential successor. In March 2018, the first session of the 13th National People's Congress passed constitutional amendments including removal of term limits for the president and vice president, the creation of a National Supervisory Commission, as well as codifying the leading role of the CCP. Xi was reappointed as president, now without term limits, while Li Keqiang was reappointed premier. In its sixth plenary session in November 2021, the 19th Central Committee adopted the Resolution on the Major Achievements and Historical Experience of the Party over the Past Century, which evaluated the party's historical legacy from its foundation in 1921 until its 100th anniversary in 2021. The third historical resolution after the ones adopted by Mao and Deng, Xi's one did not herald a major change in how the CCP evaluated its history in comparison. To accompany the resolution, the CCP promoted the terms Two Establishments and Two Upholds, calling the CCP to unite around and protect Xi's core status within the party. The 20th Party National Congress, held between 16 and 22 October 2022, has overseen amendments in the CCP constitution, with the overall result of the Congress further strengthening Xi's power.
Mirzayanov was arrested on 22 October 1992 and sent to Lefortovo prison for divulging state secrets. He was released later because "not one of the formulas or names of poisonous substances in the Moscow News article was new to the Soviet press, nor were locations ... of testing sites revealed." According to Yevgenia Albats, "the real state secret revealed by Fyodorov and Mirzayanov was that generals had lied—and were still lying—to both the international community and their fellow citizens." Mirzayanov now lives in the U.S. Further disclosures followed when Vladimir Uglev, one of Russia's leading binary weapons scientists, revealed the existence of A-232/Novichok-5 in an interview with the magazine Novoye Vremya in early 1994. In his 1998 interview with David E. Hoffman for The Washington Post the chemist claimed that he helped invent the A-232 agent, that it was more frostproof, and confirmed that a binary version has been developed from it. Uglev revealed more details in 2018, following the poisoning of the Skripals, stating that "several hundred" compounds were synthesised during the Foliant research but only four agents were weaponised (presumably the Novichok-5, −7, −8 and −9 mentioned by other sources): the first three were liquids and only the last, which was not developed until 1980, could be made into a powder. Unlike the interview twenty years earlier, he denied any binary agents were developed successfully, at least up until his involvement in the research ceased in 1994.
== History == 4-HO-DPT was first described in the scientific literature by David Repke and colleagues in 1977. Subsequently, it was described in further detail by Alexander Shulgin in his 1997 book TiHKAL (Tryptamines I Have Known and Loved). The drug was encountered as a novel designer drug in Europe in 2012.
=== Bibliography === Jamaluddin, Ahmad Badawi (2007). PENGGUNAAN UBATAN TRADISIONAL DI PASAR TAMU DAN PASAR BESAR DAERAH TAWAU, SABAH: SATU TINJAUAN [USE OF TRADITIONAL MEDICINE IN WEEKLY MARKET AND MAIN MARKET IN TAWAU DISTRICT, SABAH: A REVIEW] (PDF). Conservation Biology Program School of Science and Technology (Thesis) (in Malay). pp. 1–27. Archived (PDF) from the original on 2 June 2025. Retrieved 2 June 2025 – via Universiti Malaysia Kelantan. Kustiariyah (2007). "TERIPANG SEBAGAI SUMBER PANGAN DAN BIOAKTIF" [SEA CUCUMBER AS A FOOD AND BIOACTIVE SOURCE]. Indonesian Journal of Aquatic Product Technology [Buletin Teknologi Hasil Perikanan] (in Indonesian). X (1): 1–8. Archived from the original on 1 June 2025. Damaiyanti, Dian Widya (2015). "Karakterisasi Esktrak Air Teripang Emas (Stichopus hermanii)" [Characterization Of Water Extract Gold Sea Cucumber (Stichopus hermanii)]. Denta (Jurnal Kedokteran Gigi) (in Indonesian). 9 (1): 1–8. ISSN 1907-5987. Archived from the original on 2 June 2025. Text is licensed by DENTA (Journal Kedokteran Gigi) under CC BY-NC-SA 4.0 Vaitilingon, Devarajen; Smith, Stuart; Watson, Guy; Miller, Tim; Alattas, Syed; Ong Hock, Keat; Zainoddin, Jamari; Zaidnuddin, Ilias; Azhar, Hamzah (2016). "Sea cucumber hatchery seed production in Malaysia: From research and development, to pilot-scale production of the sandfish Holothuria scabra" (PDF). SPC Beche-de-mer Information Bulletin (36): 67–75. Archived from the original (PDF) on 16 May 2021 – via Sustainable Aquaculture Research & Development (Mauritius).
Sources: en.wikipedia.org
== Description == Lonicera japonica is a twining vine able to climb up to 10 m (33 ft) high or more in trees, with opposite, simple oval leaves 3–8 cm (1+1⁄4–3+1⁄4 in) long and 2–3 cm (3⁄4–1+1⁄4 in) broad. When its stems are young, they are slightly red in color and may be fuzzy. Older stems are brown with peeling bark, and are often hollow on the inside. The flowers are double-tongued, opening white and fading to yellow, and sweetly vanilla scented. The fruit, which is produced in fall, is a black spherical berry 3–4 mm (1⁄8–3⁄16 in) diameter containing a few seeds.
== Production == The series is a Movistar Plus+ original, produced in collaboration with Suma Content. Shooting locations in Catalonia included Barcelona, Girona, Mataró, Òrrius, Santa Eulàlia de Ronçana, Calaf, Arenys de Mar, Manresa, Gualba, and Santa Susanna. The series was lensed by Gris Jordana. Raül Refree (score) and Hidrogenesse (original songs) were responsible for the music.
Pain: Sacral, coccygeal (tailbone), gluteal, groin, rectum, and perineal regions Sciatica and leg pain Foot and toe pain Persistent genital arousal disorder (PGAD) or pudendal neuralgia Neuropathic pain characterized by burning (dysesthesia), aching, or stabbing sensations Sensory Disturbances: Paresthesias such as tingling, electric shocks, buzzing or internal vibrations Fasciculations (muscle twitching) Numbness or other sensory deficits Motor Dysfunction: Muscle weakness (Paresis) in the legs and feet Toe cramping and muscle spasms Foot Drop (Rarely) Bladder, Bowel, Sexual Dysfunction: Neurogenic bladder: urinary retention, hesitation, Valsalva voiding, increased frequency and urgency, painful bladder, urge incontinence, and stress incontinence. Neurogenic bowel: constipation, diarrhea, cramping, urgency, changes in defecation frequency, false urge to defecate, fecal incontinence, anal sphincter pain or pressure. Erectile dysfunction; retrograde ejaculation Positional Aggravation: Symptoms are typically worsened by standing, walking, sitting, or bending Lying down (recumbency) may provide partial or temporary symptom relief
The "Cave of the Painters" (Malerhöhle, 画家窟, Cave 207) is one of the earliest caves of Kizil, and one of the most beautiful. The cave contained a statue of the Buddha against the rear wall of the cella, and a barrel-vaulted ambulatory surrounded it. The main cellar contained nine murals of the preaching Buddha on each side wall. The name of the cave comes from the numerous self-portraits of painters standing at the side of the murals, holding paint cupellas and brushes. Several of the painters have a label, such as the written label in Sanskrit (Gupta script): "Painting of Tutuka" ( Citrakara Tutukasya) next to the painter in question. "Citrakara" is not Tocharian, but Sanskrit (and later Hindi, चित्रकला) for "painter/ painting". In the art of Kizil identifying labels were often added to pictures of donors, but never to narrative scenes. Paleography, stylistic analysis and carbon dating combine to give a date of circa 500 CE for these paintings. Some stylistic elements have a strong Classical touch, such as Roman-style friezes at the top of the walls, over scenes of the Buddha. The Cave of the Painters, as some other caves at Kizil, depicts men in caftans with a triangular collar on the right side, and a unique hairstyle. Another marker is the two-point suspension system for swords, which seems to have been a Hephthalite innovation, and was introduced by them in the territories they controlled. These paintings appear to have been made during Hephthalite rule in the region, circa 480–550 CE.
Aspartic acid was first discovered in 1827 by Auguste-Arthur Plisson and Étienne-Ossian Henry by hydrolysis of asparagine, which had been isolated from asparagus juice in 1806. Their original method used lead hydroxide, but various other acids or bases are now more commonly used instead. There are two forms or enantiomers of aspartic acid. The name "aspartic acid" can refer to either enantiomer or a mixture of two. Of these two forms, only one, "L-aspartic acid", is directly incorporated into proteins. The biological roles of its counterpart, "D-aspartic acid" are more limited. Where enzymatic synthesis will produce one or the other, most chemical syntheses will produce both forms, "DL-aspartic acid", known as a racemic mixture. In the human body, aspartate is most frequently synthesized through the transamination of oxaloacetate. The biosynthesis of aspartate is facilitated by an aminotransferase enzyme: the transfer of an amine group from another molecule such as alanine or glutamine yields aspartate and an alpha-keto acid.
Sources: en.wikipedia.org
A maleimide moiety reacts with the thiol of cysteine-34, forming a covalent bond. The reaction occurs in circulation without enzymatic catalysis.
The group is intended to alter distribution and persistence, not receptor engagement. The peptide portion still binds the pituitary receptor, so the primary difference is duration rather than potency.
Not firmly. Early reports describe several days for the extended form, but independent confirmations are sparse, and values vary with assay method and study design.
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.