This is a working overview of Maleimide chemistry, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-04-18 and is reviewed periodically as new material appears.
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.
Both forms act at the pituitary receptor for growth hormone-releasing hormone and increase growth hormone output, which in turn raises insulin-like growth factor 1. A long-acting analog produces sustained rather than pulsatile stimulation, and the physiological consequences of that pattern are not fully settled. Published human data on the extended form remain limited, and much of what circulates in discussion traces to early company reports rather than independent replication. How sustained exposure affects normal feedback remains an open question.
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.
| 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 |
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.
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.
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.
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.
=== Metabolomics === Borchers has also applied MRM-based mass spectrometry to targeted metabolomics. With Jun Han, he developed an LC–MS/MS method for profiling bile acids in human and mouse blood, combining the assay with a phospholipid-depletion solid-phase extraction step, which allowed a number of minor bile acids to be quantified in blood for the first time. The same collaboration produced a method for quantifying short-chain fatty acids in human feces, in which the acids are chemically derivatized with 3-nitrophenylhydrazine and measured against isotope-labelled internal standards.
== Culture == In July 1977, a New York Times article describing new plastic surgery techniques which could partially correct the appearance of those with Treacher Collins syndrome was widely circulated resulting in raised awareness of the disease. Prior to beginning his comedy career, Bob Saget made a documentary short called "Through Adam's Eyes" documenting his young nephew's experiences undergoing facial reconstructive surgery due to Treacher Collins; the film won a Student Academy Award. The disorder was featured on the show Nip/Tuck, in the episode "Blu Mondae". TLC's Born Without a Face features Juliana Wetmore, who was born with the most severe case in medical history of this syndrome and is missing 30%–40% of the bones in her face. In 2010, BBC Three documentary Love Me, Love My Face covered the case of a man, Jono Lancaster, with the condition. In 2011, BBC Three returned to Jono to cover his and his partner Laura's quest to start a family, in So What If My Baby Is Born Like Me?, which first aired as part of a BBC Three season of programmes on parenting. The first film was replayed on BBC One shortly ahead of the second film's initial BBC Three broadcast. Lancaster's third BBC Three film, Finding My Family on Facebook, which looked at adoption, aired in 2011. Lancaster's memoir about living with the condition, Not All Heroes Wear Capes, published in 2023. In Wonder, a children's novel written by R. J. Palacio, the main character is a child who has Treacher Collins syndrome.
The monocled cobra (Naja kaouthia) is a medically important species as it is responsible for a considerable number of bites throughout its range. The major toxic components in the Monocled cobras venom are postsynaptic neurotoxins, which block the nerve transmission by binding specifically to the nicotinic acetylcholine receptor, leading to flaccid paralysis and even death by respiratory failure. The major α-neurotoxin in Naja kaouthia venom is a long neurotoxin, α-cobratoxin; the minor α-neurotoxin is different from cobrotoxin in one residue. The neurotoxins of this particular species are weak. The venom of this species also contains myotoxins and cardiotoxins. The median lethal dose (LD50) is 0.28–0.33 mg per gram of mouse body weight. In case of IV the LD50 is 0.373 mg/kg, and 0.225 mg/kg in case of IP. The average venom yield per bite is approximately 263 mg (dry weight). The monocled cobra causes the highest fatality due to snake venom poisoning in Thailand. Envenomation usually presents predominantly with extensive local necrosis and systemic manifestations to a lesser degree. Drowsiness, neurological and neuromuscular symptoms will usually manifest earliest; hypotension, flushing of the face, warm skin, and pain around bite site typically manifest within one to four hours following the bite; paralysis, ventilatory failure or death could ensue rapidly, possibly as early as 60 minutes in very severe cases of envenomation. However, the presence of fang marks does not always imply that envenomation actually occurred.
Sources: en.wikipedia.org
== Research == Roy's researches during his stint in the US was on protein folding and nuclear magnetic resonance studies of DNA and those researches identified the first hydropathy model which helped in predicting the exteriors and interiors of proteins by analyzing sequence information. He is also reported to have performed the complete assignment of a nucleic acid imino proton spectra using Nuclear Overhauser effect, regio-specific isotope labeling of sugars in nucleic acids and working along with Ad Bax and R. H. Griffey, developed an indirect 2D-NMR detection method, all reported to be for the first time. Later focusing his attention on bacteriophage lambda, he studied the gene expression of the bacterial virus using its operator-repressor system. Through his collaborative work with Sankar Adhya in 1998, he elucidated the role of differential contact in the transcription regulation mechanism and demonstrated the theory in many genetic regulatory circuits. His current work is focused on peptide therapeutics and he holds patents for some of his work. Roy has published his research work through a number of articles published in peer-reviewed journals and ResearchGate, an online repository of scientific papers, has listed 155 of them. He is the Co-author of "Chemical Biology of the Genome" published by Elsevier/AP. He is a joint editor of Subcellular Biochemistry, volume on Proteins: Structure, Function, and Engineering published by Plenum Press, New York, USA and Protein-Protein interaction Regulators published by Royal Society of Chemistry, UK.
At the northern end of Via Roma stands Piazza Castello, regarded as the heart of the city. The half-pedestrianised square hosts some significant buildings such as Palazzo Reale (Former Savoy Royal House), the Palazzo Madama (which previously hosted the Savoy senate and, for few years, the Italian senate after Italian unification), the former Baroque Teatro Regio di Torino (rebuilt in modern style in the 1960s, after being destroyed by fire), the Royal Library of Turin which hosts the Leonardo da Vinci self-portrait, and the baroque Royal Church of San Lorenzo. Moreover, Piazza Castello hosts a Fascist era building, the Torre Littoria, a sort of skyscraper which was supposed to become the headquarters of the Fascist party, although it never served as such. The building's style is quite different from the Baroque style of Piazza Castello. The square regularly hosts the main open space events of the city, live concerts included.
=== Marriage and family === Sanger married Margaret Joan Howe (not to be confused with Margaret Sanger, the American pioneer of birth control) in 1940. She died in 2012. They had three children—Robin, born in 1943, Peter born in 1946 and Sally Joan born in 1960. He said that his wife had "contributed more to his work than anyone else by providing a peaceful and happy home."
Sources: en.wikipedia.org
== External links == An Extremely Detailed Map of the 2024 Election from The New York Times "Misinformation Dashboard: Election 2024. A tool tracking the topics and tactics of 2024 election misinformation". News Literacy Project. 2024. Retrieved September 30, 2024. Dovere, Edward-Isaac (November 6, 2024). "Where Harris' campaign went wrong". CNN. Retrieved November 7, 2024. "The Choice 2024: Harris vs. Trump". Frontline. Season 43. Episode 2. September 24, 2024. PBS. WGBH. Retrieved November 28, 2024. "The VP Choice: Vance vs. Walz". Frontline. Season 43. Episode 3. October 8, 2024. PBS. WGBH. Retrieved November 28, 2024.
The three substrates of this enzyme are (S)-lactaldehyde, oxidised nicotinamide adenine dinucleotide (NAD+), and water. Its products are (S)-lactic acid, reduced NADH, and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is (S)-lactaldehyde:NAD+ oxidoreductase. Other names in common use include L-lactaldehyde:NAD+ oxidoreductase, and nicotinamide adenine dinucleotide (NAD+)-linked dehydrogenase. This enzyme participates in pyruvate metabolism.
Pseudo means 'false' or 'fake'. The etymology is from the Greek word ψεύδω (pseúdō), which means to lie or deceive. hyper means 'extreme' or 'beyond normal'. The etymology is from the Greek word ὑπέρ (hupér), which means over, above; beyond, to the extreme. trophy means 'nourishment', or 'development'. The etymology is from the Greek word τροφή (trophḗ), which means food, nourishment. The term was used by Duchenne de Boulogne in his description of Duchenne muscular dystrophy in one of his works "paralysie musculaire pseudo-hypertrophique."
However, the reduction of seizure threshold could be attributed to tramadol's putative inhibition of GABAA receptors at high doses (significant inhibition at 100 μM). In addition, desmetramadol is a high-affinity ligand of the DOR, and activation of this receptor could be involved in tramadol's ability to provoke seizures in some individuals, as DOR agonists are well known for inducing seizures. Nausea and vomiting caused by tramadol are thought to be due to activation of the 5-HT3 receptor via increased serotonin levels. In accordance, the 5-HT3 receptor antagonist ondansetron can be used to treat tramadol-associated nausea and vomiting. Tramadol and desmetramadol themselves do not bind to the 5-HT3 receptor.
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.